US3189338A

US3189338A - Apparatus for controlling buckle in heated steel billets

Info

Publication number: US3189338A
Application number: US168970A
Authority: US
Inventors: Paul E Smith
Original assignee: Morgan Construction Co
Current assignee: Siemens Industry Inc
Priority date: 1962-01-26
Filing date: 1962-01-26
Publication date: 1965-06-15
Anticipated expiration: 1982-06-15
Also published as: FR1345451A; BE627498A; DE1228646B; GB995297A

Description

June 15, 1 965 3,189,338

APPARATUS FOR CONTROLLING BUCKLE IN HEATED STEEL BILLETS P. E. SMITH 2 Sheets-Sheet 1 Filed Jan. 26, 1962 H o'rneys June 15, 1965 P. E. SMITH APPARATUS FOR CONTROLLING BUCKLE IN HEATED STEEL BILLETS Filed Jan. 26, 1962 2 Sheets-Sheet 2 INVENTOR. Paul E; Smith United States Patent 3,189,338 APPARATUS FOR CONTROLLDJG BUCKLE IN HEATED STEEL BELLETS Paul E. Smith, Worcester, Mass, assignor to Morgan Construction Company, Worcester, Mass., a corporation of Massachusetts Filed Jan. 26, 1962, Ser. No. 168,970 6 tCiaims. ((21. 266-) This invention relates generally to an apparatus and method for traversing a steel billet across a holding furnace hearth and more particularly to a method and apparatus for preventing buckling of a heated billet during the push-out operation.

One of the methods now in use in the steel industry to convey a plurality of individually charged billets across a furnace hearth is the use of a broadwise actuated ram mechanism which will engage each of the individual billet member as they are endwise inserted at one end of the furnace. Repeated cycling of the ram mechanism forces the billet broadside a distance sufficient to allow a second billet to be endwise charged to take the place thereof. Repeated cycling of the ram mechanism forces the aligned billet members across the furnace hearth to the opposite end thereof where a push-out arm acts on the end of the billet to eject the heated billet from thefurnace. This method has proven entirely satisfactory as long as billet lengths are kept under 35 foot lengths. However, recent innovations in the manufacture of steel and its subsequent processing has resulted in a demand for longer billet lengths up to the magnitude of 90 feet. By providing billet lengths which are in excess of 35 feet, larger coils may be produced during the subsequent rolling operation. The increase in coil size from the average of 800 lbs., now produced by conventional methods, to coils weighing 2000 lbs. ultimately saves handling of coils, results in bigger bundles and increases the efiiciency and economy of the metal rolling operation. The conventional method of handling billet lengths of this size or anything greater than 35 feet has resulted in buckling of the billet within the furnace due to the frictional resistance of hearth and the weight of the billet, counteracting and resisting the forces exerted by the push-out arm on the end of the relatively flexible heated billet. Since these billets normally are dimensioned 2%" x 2% x 88 feet, they have a weight of approximately 2000 lbs., and any buckle which takes place within the furnace area itself causes extreme difiiculty which may require the shut-down of the furnace until the cobble can be removed. As these billets are normally heated to approximately 2100 F. buckling may cause a fusion of the cobbled member to other billets so that the entire furnace load is rendered unfit for further processing and must be discarded.

Therefore it is an object of this invention to provide an apparatus and method for traversing long billets across a furnace hearth and to minimize or eliminate the buckling during the push-out operation.

It is a further object of this invention to provide an apparatus and method for imparting an arcuate formation to normally straight dimensioned bars after they are positioned within the furnace and to maintain them in this arcuate position as they traverse across the furnace hearth to the push-out mechanism.

Patented June 15, 1965 Broadly stated in the attainment of the foregoing related advances, a holding furnace is provided having a plurality of pusher bars extending through one end wall thereof and connected to a central drive mechanism located externally of the furnace so that each of the pusher arms extends inwardly at varying distances from the end wall of the furnace with the outermost ends extending inwardly a greater distance from the end wall than those toward the center line. In this manner the free ends of the pusher bars present a curvilinear line which travels through a constant lateral path in response to the movement of the central drive mechanism.

To the accomplishment of the foregoing and related ends, the present invention then consists of the means hereinafter fully described, and particularly pointed out in the claims, the annexed drawing and the following description setting forth in detail certain means of carrying out the invention, which disclosed means illustrating, however, but one of the various ways in which the principles of the invention may be employed. The present invention is illustrated by way of example.

In the accompanying drawings in which:

FIG. 1 is a top plan view partly in section of the furnace embodying features of this invention;

FIG. 2 is a view in section taken on line 2--2 of FIG. 1; and

FIG. 3 is a view in section taken on line 33 of FIG. 1.

Reference is now to be had to the drawings where an illustrated embodiment of the holding furnace construction made in accordance with the present invention and generally designated by the reference numeral 10 is shown. The furnace construction 19 is of the conventional type having end walls 12 and 14 and side walls 16 and 18. The side wall 16 has an aperture 20 formed therein adjacent the end wall 12 and adapted to receive a billet 22 which is presented endwise by an arm 24 of charging mechanism 26. The charging mechanism 26 is of the reciprocating type and is adapted to linearly travel along rollers 28 which are driven by a motor 30 through a suitable reduction gear 32 to aid in conveying the billet 22 to the interior of the furnace 10. On the same side wall 16 of the holding furnace 10 and at a point adjacent the end wall 14 a similar aperture 34 is formed adapted to receive a push-out arm 36 which is actuated through a suitable reciprocating mechanisrn 38 and which serves to eject the billet after it has travelled across the hearth 40 of the holding furnace 10. On the opposing side wall 18 adjacent the end wall 14, and in alignment with the aperture 34 is another aperture 42 which allows discharge of a billet fr'om the furnace where it is channelled by guide means 44 to roll stand 46 which lies directly in the path of further rod processing equipment (not shown).

Spaced from the end Wall 12, but parallel thereto, is a reciprocating ram mechanism 48 including a motor 5t) and a reduction gear 52 which drives a longitudinally extending shaft 54 coupled at the ends to transversely extending

arms

56 and 58. The

arms

56 and 58 are adapted for movement by means of gearing 59 which converts the rotary motion of the shaft 54 into linear motion along a plane normal to the end wall 12. As can be seen from referring to FIG. 1 the

arms

56 and 58 are secured to a longitudinally extending bar member 60 which is adapted for corresponding movement therewith. A plurality of pusher bars 62 which move in the same direction as the

arm members

56 and 58 are connected at one end to the bar member 60 and adapted to ride on suitable bearings 64. A plurality of corresponding apertures 66 are formed in the end wall 12 in axial alignment with the pusher bars 62 to permit the entry of the pusher arms within the interior of the furnace 10. The pusher bars 62 are of different lengths with the shorter bars situated substantially at the center of the end wall 12 and the bars extending on either side of the center bar incrementally longer than the preceding bars so that the outermost bars extend inwardly a greater distance from the interior edge 67 of the end wall 12 than the centermost arms. In this manner a line'drawn connecting the free ends 68 of the pusher arms 62 will define an arcuate path.

Referring to FIG. 2 there is shown a cross sectional elevation of the furnace illustrating the hearth 4t having a concave shape so that the center portion 7% curves downwardly from

theportions

72 and 74 which are adjacent the side walls 16 and 18. The action of the charging arm 36 on the end of the billet 22 to eject the billet from the furnace through the opening 44 so that it may ,be picked up by the guide 44 for delivery to the roll stand 46 is thereby shown.

In FIG. 3 there is shown an enlarged view in section of the pusher bars 62 extending through the end wall 12 before the pusher bars have been actuated by the operating mechanism 48 and illustrate the billet 22 in position to receive a broadside thrust from the pusher bars 62.

In the operation of this apparatus the billets 22 are charged into the furnace by the charging arm 24 so as to lie at a position which is spaced from the end wall 12. The motor 50 operating through the reduction gear 52 rotates the shaft 54 to impart a transverse motion to the

arms

56 and 58 which in turn moves the pusher bars 62 by means of the longitudinally extending bar member 66 so that each of the bar members 62 moves simultaneously with each other to impart a broadside motion to the billets 22. In this manner it will be seen that the outermost pusher bars 62 make contact with the billet member first, forming the billet into an arcuate shape and at the same time pushing it away from the end wall 12. As successive billets are presented by the charging mechanism 26 they are similarly acted upon by the pusher bar 62 and impart a thrust to previously charged billets which have already been transversely moved along the furnace hearth floor 40. The hearth 40 having a concave configuration allows the billet 22 to curve downwardly at the center portion so that the ends 76 and 78 are in a higher plane than the center portion. The broadwise force exerted on each newly presented billet 22 by the pusher bars 62 is also imparted to the billets already in the furnace until the furnace is fully charged. The push-out arm 36 is synchronously timed with the charging mechanism 26 to eject the billet after it has passed across the hearth. The billet 22 after passing across the furnace hearth has been raised to a temperature in the range of 2100 and as the push-out arm 36 acts on the end of the billet to eject it from the furnace the billet has a pre-disposition to buckle in the direction of the concave surfaces. The billet, however, is prevented from buckling by the weight of the successively horizontal stacked billets which extend in the direction of the concavity and also by the force exerted on them by the pusher bars 62. Furthermore, to aid in keeping the billets with their lateral surface in abutting relationship, the hearth 40 may be inclined upwardly from the'rear Wall 12 toward the front wall 14, as shown in FIG. 3 in broken lines. In this manner the gravitational effect on the billets will maintain an opposing force relative to the action of the pusher bars 62. The billet 22 also has a tendency to buckle downwardly due to the arcuate formation presented to it by the formation of the concave hearth but is resisted from doing so by the 'hearth itself. Consequently, any tendency of the billet to buckle in the direction of either of its arcuate formations is prevented, and since the billet would have to overcome the deformation of the center position and go beyond a straight linear dimension before it could buckle either upwardly or in a direction opposite to its horizontal deformation, buckling of the billet during the ejection stage is circumvented.

Therefore, a ram mechanism utilizing pusher bars having varying lengths to impart an arcuate formation to the billet length and having a hearth which also allows a downward arcuate formation to the bar member permits the use of billets which are in excess of 35 feet without the danger of buckling during the push-out operation.

Since certain obvious modifications may be made in this apparatus without departing from the scope thereof, it is intended that all matter contained herein be interpreted in an illustrative and not in a limiting sense.

I claim:

ll. Apparatus for conveying a plurality of billets through a furnace having side and end walls, said apparatus including means for successively charging one end of the furnace with billets, a reciprocating ram mechanism having a plurality of laterally spaced pusher bars of varying lengths extending into said furnace through one end wall thereof with the outermost pusher bars extending inwardly a greater distance from said end wall than the innermost pusher bars, means for imparting motion to said ram mechanism so that said pusher bars exert a force on each billet normal to its greater dimension, and push-out means acting on one end of the billet and disposed adjacent the opposite end wall of said furnace to remove individual billets from the furnace.

2. Apparatus as set forth in claim 1 where the furnace hearth slopes upwardly from the end wall containing the pusher bars to the opposite end wall.

3. Apparatus for traversing billets across a furnace hearth having side and end walls, said apparatus including means for successively charging one end of said furnace with individual billets presented endwise through a side wall of the furnace, a reciprocating ram mechanism adjacent one end wall of the furnace having a plurality of laterally spaced pusher bars with end portions extending within said furnace, said pusher bars being of varying lengths so that the end portions define an arcuate line relative to the end wall, means for imparting motion to said ram mechanism so that said pusher bars exert a force on each billet normal to its greater dimension and push-out means extending through said side wall adjacent the opposite end wall to eject the billets from said furnace.

4. An apparatus as defined further in claim 3 where said furnace hearth has a concave configuration with the area adjacent the side walls having a higher elevation than the center section.

5. Apparatus for conveying a plurality of billets through a furnace having side and end walls, said apparatus including means for successively charging endwise presented billets into one end of the furnace, a plurality of laterally spaced pusher bars of varying lengths extending through one end wall of said furnace with the outermost pusher bars extending inwardly a greater distance from said end wall than the innermost pusher bars, means acting on said pusher bars to direct them normal to the greater dimension of said billets, the hearth surface of said furnace having a concave configuration with the area adjacent to the side walls at a higher elevation than the center section, said furnace hearth sloping upwardly from said one end wall of the furnace to the other end wall and pusher means adjacent said other end wall adapted to eject said billets from the furnace.

6. A heating furnace for metal billets comprising side walls, front and rear walls, and a hearth sloping upwardly from the rear wall to the front wall, said hearth having a concave surface with the area adjacent the side walls having a higher elevation than the center section, means for successively charging endwise presented billets through one apertured side wall adjacent the rear wall, a plurality of laterally spaced pusher bars extending through the rear wall into said furnace, means for imparting a motion to said pusher bars normal to the greater dimension of said billets, the end portions of each of said pusher bars disposed Within said furnace and spaced from the rear Wall at varying distances so that the centermost end portion is closest to the rear wall and the pusher bar end portions on either side thereof are spaced incrementally a greater distance from said rear Wall, and push-out means extending through said one side Wall adjacent the front end Wall adapted to eject said billets from the furnace.

References Cited by the Examiner UNITED STATES PATENTS 2,616,679 11/52 Morgan 2636 X 3,055,650 9/62 Morgan 263-6 MORRIS O. WGLK, Primary Examiner.

DAVID L. RECK, Examiner.

Claims

1. APPARATUS FOR CONVEYING A PLURALITY OF BILLETS THROUGH A FURNACE HAVING SIDE AND END WALLS, SAID APPARATUS INCLUDING MEANS FOR SUCCESSIVELY CHARGING ONE END OF THE FURNACE WITH BILLETS A RECIPROCATING RAM MECHANISM HAVING A PLURALITY OF LATERALLY SPACED PUSHER BARS OF VARYING LENGTHS EXTENDING INTO SAID FURNACE THROUGH ONE END WALL THEREOF WITH THE OUTERMOST PUSHER BARS EXTENDING INWARDLY A GREATER DISTANCE FROM SAID END WASLL THAN THE INNERMOST PUSHER BARS, MEANS FOR IMPARTING MOTION TO SAID RAM MECHANISM SO THAT SAID PUSHER BARS EXERT A FORCE ON EACH BILLET NORMAL TO ITS GREATER DIMENSION, AND PUSH-OUT MEANS ACTING ON END OF THE BILLET AND DISPOSED ADJACENT THE OPPOSITE END WALL OF SAID FURNACE TO REMOVE INDIVIDUAL BILLETS FROM THE FURNACE.