US2757444A

US2757444A - Composite assembly for metal cladding

Info

Publication number: US2757444A
Application number: US256105A
Authority: US
Inventors: Thomas B Chace
Original assignee: Clad Metals Industries Inc
Current assignee: Clad Metals Industries Inc
Priority date: 1951-11-13
Filing date: 1951-11-13
Publication date: 1956-08-07
Anticipated expiration: 1973-08-07

Description

WE?" "11'. B. QHACE 2,,

COMPOSITE ASSEMBLY FOR METAL CLADDING Filed Nov. 13, 1951' 2 Sheets-Sheet l mm, K W% T. B. cHAm: 2 7%7 M4 COMPOSITE ASSEMBLY FOR METAL CLADDING Filed Nov. 13, 1951 2 Sheets-Sheet 2 v BY \\\\W\ WZ United 2,757,444 Patented Aug. 7, 1956 COMPOSITE ASSEMBLY FOR METAL CLADDING Thomas B. Chace, Winnetka, 11]., assignor to Clad Metals Industries, Inc., Chicago, 111., a corporation of Illinois Application November 13, 1951, Serial No. 256,105 1 Claim. (Cl. 29-187.5)

The present invention relates to clad metals and particularly to composite assemblies for metal cladding.

In cladding one metal with another, it is customary to confine a bar or block of relatively soft metal within a boxing of relatively hard metal and run the composite block or billet through a plurality of compressing rolls to effect a fusion of the two metals. By way of example, a block of copper may be suitably confined between two plates of stainless steel in the manner stated to provide copper clad stainless steel. The present invention has particular adaptability to the formation of copper clad stainless steel and, accordingly, the following description will be directed to these two metals. It will be understood, however, that references to copper and stainless steel may equally apply to other metals and that the two metals are chosen as exemplary of the adaptability of the present invention and not as restrictions thereon.

To clad stainless steel with copper, it is essential that the surfaces of the copper and steel be completely clean and non-oxidized. Accordingly, it has been customary to thoroughly clean the surface of the two metals and to completely enclose the copper in a stainless steel box to prevent oxidation of the abutting surfaces ofthe steel and copper. A further requirement for completely enclosing the copper is to prevent the soft copper from being squeezed out of the space between the hard steel plates during passage of the composite block or billet through the compressing rolls. The steel box has usually and conveniently been made up by inserting a block of copper between two steel plates and welding side plates to the side edges of the steel plates to completely enclose the copper block.

The composite billet thus formed has been generally accepted in the industry, but has suliered many disadvantages, the most prominent of which is the readines with which the box breaks up at its lead end during the first pass through the pressing rolls. For example, as the lead end of the box is inserted between the first set of rolls, the welded seams frequently fracture with the result that the side plate at the lead end of the box is broken away and air enters between the steel plates and the copper blocs and oxidizes the metal] surfaces and prevents fusion of the two metals. in addition, the soft copper is then free to spread outwardly of the boxing from be son the steel plates under rolling pressure.

An object of the present invention is to overcome the stated disadvantage by providing a novel boxing construction or composite assembly including a block leader end.

Another object of the invention is to provide a hard metal block leader end for netal cladding composites to prevent fracture and breaking of the lead end of the composite.

A further object of the invention is the provision of improved composite assemblies for metal cladding adapted to withstand the forces of the pressing rolls without fracture to insure a proper bond between the metals.

A still further object of the invention is the provision of a T-block leader end for metal cladding composites, the leader end having cooperative association with the plates to be clad to prevent disassociation of the plates and the leader end.

Conventional composite assemblies suiler the further disadvantage of requiring several elements in their construction and a somewhat difiicult and tedious manner assembly.

it is an object of the present invention to overcome this further disadvantage of conventional composites by providing integral shaped elements constituting the plates and side plates of the harder metal or steel boxing, so as to eliminate some of the elements and assembly steps of conventional composites.

Other objects and advantages of the present invention will become apparent in the following detailed description of preferred embodiments of the invention, wherein reference is made to the accompanying drawings, in which:

Figure l is a perspective view of a composite billet formed according to the present invention;

Figure 2 is a perspective view, on an enlarged scale, of the T-block leader end of the present invention;

Figure 3 is a side elevation of the leading end of the composite billet shown in Figure 1;

Figure 4 is a partial plan view of the leading end of a modified composite billet formed according to the present invention;

Figure 5 is a vertical cross-sectlon taken substantially on the line 5-5 of Figure 4;

Figure 6 is a partial plan view of the leading end of a further modification of the composite billet of the present invention;

Figure 7 is a vertical cross-section on the line 7-? of Figure 6;

Figure 8 is a perspective view of the leading end of another modification of the composite billet of the present invention;

Figure 9 is a side elevation of the leading end of a composite billet of the present invention, including a modified box or mold construction and assembly;

Figure 10 is a cross-sectional view taken substantially on the line 10ltl of Figure 9;

Figure ll is a side elevation of the leading end of a composite billet formed according to the present invention, including a further modified box construction and assembly;

Figure 12 is a cross-sectional view taken substantially on the line l2-l2 of Figure ll; and

Figure 13 is a cross-sectional View, similar to Figures 10 and 12, of another modified box construction and assembly according to the present invention.

Referring now to the drawings, and particularly to Figures l, 2 and 3, there is shown a composite billet which is conventional in form except for the leading end thereof. The composite preferably comprises a relatively thick bloc of copper or other relatively soft cladding metal 20 and a boxing of relatively hard metal therefor. The boxing comprises a pair of relatively thin steel or other relatively hard'metal plates 22, abutting opposite sides of the copper biock 2t and adapted to be copper clad, and a plurality of side plates 24 which are suitably secured to the relatively hard metal plates 22, preferably by welding. T he side plates 24 are preferably formed of steel, or the same material as the plates 22, and are of the same width as the thickness of the copper block 2% The steel plates 22 are preferably of greater plan dimension than the copper block 2% so as to project beyond the ends and sides of the copper block. The side plates 24 are adapted to be inserted at the edges of the block 20 be tween the plates 22 and may be suitably welded to the plates. The surfaces of the copper block 20 and the taken substantially steel plates 22 are cleaned before assembly to remove any dirt or oxidized materials. At the leading end of the composite billet, the plates 22 extend a substantial distance beyond the leading end of the copper block 2%, preferably a distance substantially in excess of the thickness of the respective plates, but the side plates 24 terminate atthe leading end of the copper block. The extending end portions of the plates 22 are adapted for the reception therebetween of a T-block leader end 26.

The T-block leader end 26 is preferably of the same width as the plates 22 and is provided with a reduced shank or stem 28, of the same thickness as the copper block 20, adapted for insertion between the extending end portions of the plates 22. The shank 28 is preferably of a length equal to the length of the extending end portions of the plates 22 so that the free end of the shank abuts the leading end of the copper block. As is clearly shown in the drawings, for example in Figure 3, the shank 28 is of a length greater, and preferably substantially greater, than the thickness of the

plates

22 and 24 of the boxing. With reference to a somewhat shortened shank, as shown in Figure 9, it is there clearly shown that the length of the shank is also greater than the thickness of the boxing parts, and that the length of the shank should be no less, and preferably greater, than one-half the thickness of the composite assembly of the relatively soft metal block and the relatively hard metal boxing. The T-block leader end 26 is provided with an enlarged head 30 which is preferably of the same thickness as the combined thickness of the plates 22 and the copper block 20. The connecting or joining surfaces between the reduced shank 28 and the enlarged head 30 of the leader end 26 are preferably tapered or inclined, as indicated at 32 in Figure 2, so that when the shank 28 is inserted between the plates 22, a generally V-shaped groove is provided between the ends of the plates 22 and the head 30 of the leader end 26. The V-shaped slot or groove between the head 30 and each plate 22 is adapted for the reception of weld material, indicated at 34, to secure the leader end 26 to the plates 22. As pointed out hereinbefore, the leader end 26 is preferably formed of the same material as the relatively hard metal plates 22 so as to provide for an intimate bond therebetween and to provide substantial resistance to fracture of the leading end of the composite billet. The side plates 24 are preferably welded to the end surface of the reduced shank 28 of the leader end 26 to entirely seal the copper block within the stainless steel box or mold formed by the plates 22, the side plates 24 and the leader end 26.

In use, the T-block leader end 26 will provide substantial resistance to fracture or distortion of the leading end of the composite billet as the billet is passed through the pressing rolls. Considering Figure 3, as the head 30 of the leader end 26 is passed through the first set of pressing rolls, the head 30 will present substantial resistance to fracture or reduction and, being of the same size as the combined thickness of the plates 22 and the copper block 20, or the reduced shank 28, will provide an entry portion alleviating the load on the welded seams that has heretofore resulted in fracture at the leading end of the composite billet. As the billet passes through the rolls, the welded joints 34 will not be fractured by the pressing rolls due to the resistance to fracture presented by the relatively hard metal head and the composite assembly of the two relatively hard metal plates and the shank 28 of the leader end 26. Accordingly, the leader end of the present invention provides for the assembly of a composite billet that will not suffer fracture at its leading end during passage through conventional pressing rolls and, accordingly, the disadvantages suffered with conventional composite billets are overcome. The prevention of fracture at the leading end of thecomposite billet will allow the rolls in the first pass to effect a partial fusion between the stainless steel plates 22 and the copper block 20 so that subsequent fracture upon reduction in size of the billet will not result in an oxidation of the engaging and fused surfaces of the two metals. Use of the leader end of the present invention insures the production of uniformly and perfectly fused copper clad stainless steel.

Modifications of the composite billet shown in Figures 1, 2 and 3 are shown in Figures 4 to 7, wherein the assembly is identical to the assembly shown in Figures 1, 2 and 3, with the exception that fasteners are passed through the abutting'surfaces of the steel plates 22 and the shank '28 of the leader end 26, the shank being of a length greater than the thickness or diameter of the fasteners to receive the fasteners, whereby the leader end block is rigidly united to the-steel boxing by the fasteners. In the modification of Figures 4 and 5 the plates 22 are suitably bored and counterbored and the shank 28 of the block 26 is bored for the reception and passage of a bolt 36. T he head of the bolt 36 is received in the counterbore in one of the plates 22 and a nut 38, adapted to be threaded to the bolt 36, is received within the counterbore in the other of the plates 22. After the nut 38 has been threaded to the bolt 36 and tightened, the counterbores in the plates 22 are preferably filled with weld material, as indicated at 40. It is preferable to provide a plurality of bolts 36 across the width of the composite billet to insure a retained assembly of the leader end 26 and the plates 22.

In Figures 6 and 7, I have shown an assembly similar to that shown in Figures 4 and 5, with the exception that the fasteners are in this instance in the form of rivets 42, the heads of which are flattened to completely fill conical counterbores provided in the plates 22. Accordingly, it will be appreciated, that the counterbores in the plates 22 need not be filled with weld materials, as was the case in the embodiment of the invention shown in Figures 4 and 5. In the embodiment of the invention shown in Figures 4 and 5, the head of the bolt 36 and the nut 38 are preferably positioned substantially flush with the surfaces of the plates 22 and the weld material 40 is also flush with the surfaces of the plates 22. In Figures 6 and7, the rivets 42 have their heads flattened so as to be flush with the surface of the plates 22.

Referring now to Figure 8, a further embodiment of the composite billet of the present invention is shown, wherein the leader end comprises a rectangular block 44 rather than the T-block leader end 26 described hereinbefore. The leader end block 44 is preferably of the same thickness as the copper block 20 and of the same width as the block 20 and the side plates 24. The leader end 44 is adapted for insertion between the extending end portions of the plates 22 and may be suitably secured thereto by welding or the like. Also, or alternatively, a plurality of rivets 46 may be passed through the engaging portions of the plates 22 and the leader block 44. With regard to the embodiments of the invention shown in Figures 4 and 5 and Figures 6 and 7, the bolts 36, the rivets 42 and the rivets 46 are preferably three in number, as is shown in Figure 8.

As pointed out hereinbefore, the composite billet assembly including the plates 22 and the side plates 24 is conventional except for the leader end of the present invention, The composite assemblies including the plates 22 and the side plates 24 are not entirely satisfactory, since a plurality of pieces of metal and plurality of welds are required to effect the assembly of the hard metal boxing. To eliminate some of the parts and welding operations essential to the assembly of conventional composite billets, the present invention contemplates the provision of improved box means for inclosing a block of relatively soft metal. Referring now to Figures 9 and 10, I have shown a first embodiment of a modified boxing construction according to the present invention. The composite billet, as is shown in Figure 9, may be provided with the T-block leader end 26 described hereinbefore which is adapted to be suitably welded to the plates of the box, as indicated at 34. The box preferably comprises a pair of channel forms or U-shaped plate members 48 having their legs cut out at the leading end thereof for the reception of the shank 28 of the leader end 26. The channel forms 48 are preferably disposed in opposed relation with the legs of one form abutting the legs of the other form, so that the forms define a rectangular box adapted for the reception of the copper block 20. To secure the relatively hard metal plates formed by the channel forms 48 to one another and to confine the copper block 20 with the plates 48, the legs of the plates are suitably welded to one another, as indicated at 50. The trailing end of the composite billet including the channel forms 48 may be suitably closed by a conventional end plate, such as that shown at 24 in Figure 1, or the channel form plates 48 may be suitably provided with integral end plate portions adapted to be Welded together in much the same manner as the legs are welded together at 50. The channel or U-shaped plates 48 may be formed in any suitable manner, as by passage through forming rolls, or may be cast in any desired manner. The advantages of the composite billet formed with the channel plates 48 will be obvious.

A further modification of the composite billet boxing of the present invention is shown in Figures 11 and 12, wherein the box comprises a channel or U-shaped form of plate 52, adapted for the reception of the copper block 20, and a flat plate 53 adapted to rest on the edges of the legs of the channel form 52. The plate 53 may be secured to the legs of the channel form 52 in any desired manner, such as by welding the two together, as indicated at 54. If desired, the upper edges of the legs of the channel form 52 may be grooved for the reception of longitudinal ribs 55 provided on the plate 53. The grooves and ribs 55 provide an interlocking engagement between the channel form 52 and the fiat plate 53. As pointed out in the discussion of the embodiment of the invention shown in Figures 9 and 10, the trailing end of the composite billet formed according to Figure 12 may be sealed by a conventional end plate, or the channel form 52 may be provided with an integral end plate adapted to be suitably secured to the flat plate 53 in a conventional manner. Referring particularly to Figure 11, a modified leader end is shown for association with any one of the box assemblies of the present invention. The modified leader block is indicated generally at 56 and is provided with an integral reduced shank 58 and an enlarged head 60. The shank 58 is of the same width and thickness as the copper block 20 and is adapted to be inserted within the open leading end of the composite box formed by the channel form 52 and the plate 53. The enlarged head 60 is of the same dimensions as the box so that a continuous groove extends around the perimeter of the leader block 56 between the head 60 thereof and the end surfaces of the channel form 52 and the plate 53. The continuous groove is adapted for the reception of a continuous weld, indicated at 64, to positively secure the block leader end 56 to the relatively hard metal box.

A further modification of the box assembly of the present invention is shown in Figure 13, wherein the box comprises a channel or U-shaped plate 72, generally similar to the channel form 52, adapted for the reception of a copper block 20. A second channel or U-shaped plate 74, which is generally larger than the channel form 72, is adapted to be positioned over the open side of the plate 72 so that the legs of the channel form 74 overlap the legs of the channel form 72. The two channel forms 72 and 74 are adapted to be secured together by a weld, indicated at 76, joining the extremities of the legs of the channel from 74 to the sides of the legs of the channel form 72. The box formed according to the disclosure of Figure 13 may be suitably provided with a block leader end according to the present invention, such as any of the leaders ends 26, 44 or 56. If a leader end similar to the T-

blocks

26 and 56 is provided, the

head

30 or 60 thereof should preferably be of the size of the channel form 74. If desired, any of the relatively hard metal box assemblies of the present invention, as shown in Figures 10, 12 and 13, may be provided with a leader block of the same type as that indicated at 44.

From the foregoing, it will be appreciated that the present invention provides a leader end for composite billets adapted to prevent fracture at the leading end of the billet to insure fusion between the relatively soft metal of the billet and the relatively hard metal of the billet. The present invention also provides novel box assemblies for composite billets to more completely confine the block of relatively soft metal and to reduce the work and expense involved in the formation of a composite billet.

While I have shown what I regard to be preferred embodiments of my invention, it will be apparent that various changes, rearrangements and modifications may be made therein without departing from the spirit and scope of the present invention, as defined. by the appended claim.

I claim:

A composite billet for rolling to produce copper clad steel plates, said billet comprising a block of copper, a boxing of steel within which said copper block is confined, said boxing being laterally and forwardly open at the leading end thereof and having end portions extending beyond the leading end of said block, and a T- block leader end including a shank and an enlarged head, said shank being of substantially the same thickness as said block and of substantially the same width as the composite assembly of said boxing and said block, said shank being of a length greater than the thickness of said boxing and equal substantially to the extending end portions of said boxing, said shank being inserted between the extending end portions of said boxing in abutting engagement with the leading end of said block, said head being of substantially the same Width and thickness as the composite assembly of said boxing and said block, said shank and said head being joined by inclined surfaces, said leader end block being secured to the leading end of said boxing by weld material filling in the space between said end portions and said inclined surfaces.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Jan. 27,