US3333452A

US3333452A - Reduction of thick flat articles

Info

Publication number: US3333452A
Application number: US436886A
Authority: US
Inventors: Sendzimir Tadeusz
Original assignee: T Sendzimir Inc
Current assignee: T Sendzimir Inc
Priority date: 1965-03-03
Filing date: 1965-03-03
Publication date: 1967-08-01
Anticipated expiration: 1984-08-01

Description

Aug. 1, 1967 T. SENDZIMIR REDUCTION OF THICK FLAT ARTICLES 4 Sheets-Sheet 1 Filed March 5, 1965 a N m NW RN mvawroa TADEUSZ SENDZIMIR zwvsuron 4 Sheets-Sheet E3 321: TADEUSZ SENDZIMIR,

T SENDZIMIR REDUCTION OF THICK FLAT ARTICLES Aug. 1, 1967 Filed March Fm. U

Aug. 1, 1967 T. SENDZIMIR REDUCTION OF THICK FLAT ARTICLES 4 Sheets-Sheet 5 Filed March 5, 1865 WM, Fmiw,

.R M m D W mm VS W Z S w .r D I (w I M mm mm Aug. 1, 1967 T. SENDZIMIR REDUCTION OF THICK FLAT ARTICLES Filed March 5, 1965 4 Sheets-Sheet 4 INVENTOR. TADEUSZ Smwzmm,

United States Patent 3,333,452 REDUCTION OF THICK FLAT ARTICLES Tadeusz Sendzimir, T. Sendzimir, Inc., Waterbury, Conn. 06720 Filed Mar. 3, 1965, Ser. No. 436,886 21 Claims. (Cl. 72-184) This invention relates in part to the reduction of thick, elongated metal articles which, for convenience, will hereinafter be referred to as slabs. One of the modes of reduction contemplated in this application is a continuous process in the nature of step-wise forging either to form a finished article as such, or to form a slab to be fed into another reducing instrumentality.

The present inventor has hitherto developed mills of a planetary character capable of receiving hot slabs of substantial thickness and reducing them in a single operation to very much lesser thicknesses and in particular to sheet thicknesses, as set forth, for example, in US Letters Patent Nos. 3,138,979, 3,049,948, 2,710,550, and others. For convenience, such mills will hereinafter be referred to as planetary mills. They produce from slabs a strip material which has good quality, satisfactory surface characteristics and uniform gauge; and they are easy to maintain and capable of long uninterrupted runs.

A typical mill of this character in present operation, accepts hot slabs about 3 /2 inches in thickness, and 43 inches in width, and rolls them directly to sheet gauge strip at about 70 tons per hour. This is a large mill in which the overall diameter of the planetary assemblies is about 52 inches each.

It is frequently desirable to reduce slabs of greater thickness, say about 7 inches thick, especially if it is desired to couple the planetary mill with a continuous casting apparatus; but if aplanetary mill were constructed to reduce slabs having a thickness of 7 inches or greater, it would be necessary to provide planetary assemblies having a diameter of 104 inches or greater, which would economically be unsound.

It would be possible to use two or more planetary mills in succession, the earlier mill or mills effecting a partial reduction of the slab in a separate stage or stages to a thickness which would be accepted by the final planetary mill. However, planetary mills as such, involve considerable expense and occupy a substantial floor space so that the use of a plurality of such mills in tandem would have certain disadvantages in both cost and convenience. Further, problems would be encountered in the concurrent and synchronized operation of a plurality of such mills, as well as in an attempt to reduce an initially thick slab to sheet gauge in a single heat.

One of the objects of this invention is to provide a relatively simple and inexpensive machine for reducing heavy slabs to a thickness such as will be accepted by a given planetary mill.

In the operation of many planetary mills, it is necessary to provide a piston feeding means for causing the slab to enter the mill. Various forms of feeding means can be provided. For example, using proper tables and guides, the slab when withdrawn from a heating furnace may be pushed into a planetary mill by the piston of a fluid cylinder. This becomes more difiicult to do as the length of the slab increases so that if, for example, a slab 7 inches thick were to be substituted for a slab 3 /2 inches thick but of equal length, and if the 7 inch sla-b were rst reduced to one-half its thickness, its length wouldbe substantially doubled. On the whole the provision of a pair of series of pairs of feed rolls has been found most advantageous.

It has hitherto been suggested that the slab may be fed into a planetary mill through the use of mechanically operated shoes which engage the slab from either side and are arranged to exert a continuous forward feeding force on the slab. Such an arrangement is illustrated in US. Patent No. 2,811,060 of the present inventor. But socalled shoe-feeding means have not attained substantial success in this art for a number of reasons, one of them being that even a slight coating of scale on the surface of the slab renders that surface so slippery that the shoes are not able to transmit to the slab a sufficient feeding force.

It is an object of this invention to provide a means which can simultaneously act to effect a substantial reduction in thickness of the slab and feed it forwardly under a constant force and at a uniform speed.

It is an object of the invention to provide a novel and useful combination of a pie-reducing means and a planetary mill.

In another aspect of the invention, especially where the planetary mill has a feeding means of its own, it is an object of the present invention to provide a pre-reducing means which will not generate any such axial forces as would adversely influence the operation of other mill feeding means.

It is yet another object of the invention to provide a means for effecting a pre-reduction in the thickness of slabs, which means is relatively inexpensive and is capable of effecting such reduction continuously and repeatedly and without undue loss in the heat content of the slabs.

These and other objects of the invention which Will be set forth hereinafter, or will be apparent to the skilled worker in the art are accomplished by that procedure and through the use of that mechanism of which certain exemplary embodiments will now be described. Reference is made to the accompanying drawings wherein:

FIGURE 1 is a fragmentary and diagrammatic representation of a slab being acted upon by forging or swaging tools, illustrating certain principles of operation which are important to this invention.

FIGURE 2 is a diagrammatic sectional representation of the action of a forging or swaging tool upon a metal slab.

FIGURE 3 is a partial sectional view of the slab illustrating various stages of the forging reduction.

FIGURE 4 is a vertical section of a machine illustrating a type of forging tool drive, the sectional view being taken along the line AA in FIGURE 5.

FIGURE 5 is a cross-sectional view taken through the center line of the forging tools shown in FIGURE 4.

FIGURE 6 is a semi-diagrammatic sectional view showing a combination of the pre-reducing instrumentality of FIGURES 4 and 5 with a continuous casting unit and.

a planetary mill. I

FIGURE 7 is a partial sectional view showing another form of drive for a swaging or forging means and is related to the section line BB of FIGURE 8.

FIGURE 8 is a sectional view of the same apparatus related to the section line C-C of FIGURE 7.

FIGURE 9 is a fragmentary view partly in section and showing a means for limiting the penetration of the forging tools where the forging tools are constructed and actuated as shown in FIGURE 10.

FIGURE 10 is a view with parts in section, of a reducing instrumentality arranged to reduce the thickness of a slab and to feed it directly into a planetary mill.

FIGURE 11 is a partial sectional view through means shown in FIGURE 9.

FIGURE 12 is an end elevational view with parts in section of the apparatus of FIGURE 10.

While a large field of utility for the swaging and forging apparatus hereinafter described lies in the pre-reduction of slabs and the direct feeding of the pre-reduced slabs into a planetary mill, and while the invention will generally be so described, it will be understood that a planetary mill does not constitute a limitation on the present invention excepting as set forth in the appended claims. The swaging and forging means of this inVentiOn are capable of use wherever it is desired to reduce a heavy thickness of metal such as a slab to a lesser thickness; and they are capable of use with other reducing instrumentalities than the planetary mill.

As diagrammatically illustrated in FIGURE 1, the original slab thickness, indicated at 2, of the slab 1 is reduced to a thickness indicated at 3 by the coaction of at least two forging tools 4 and 5. These tools engage a short length of the slab 1, and for the purpose of this initial explanation the tools 4 and 5 may be considered as unitary elements of sufficient dimension to engage the slab across its whole width. The slab will be at a high temperature (e.g. 1900 F. for an iron or mild steel slab) to impart plasticity to the metal; and the movement of the tools 4 and 5 toward each other when in contact with the slab compresses the slab and thereby reduces its thickness. The shaping of those surfaces of the tool which engage the slab is very important. It will be noted in FIG- URE 1 that each tool has a fiat 7 which is either parallel with the axis of the slab 1 or is slightly negatively inclined with respect thereto, so that the thickness 3 of the slab is slightly less at the left-hand side of the fiat 7 than at its right-hand side. A surface 9 is provided on the tool which lies at a substantial angle to the fiat 7 (usually between 40 and 50 to the axis of the slab); and the surface 9 merges into a trailing surface of the tool through slightly curved transition areas indicated at 8, 8.

In this aspect of the invention during the forging stroke when the tools 4 and 5 are moving toward each other and engage the slab 1, the frictional and reverse forces generated between the tools and the surfaces of the slab are so high,as to prevent axial components of the forging pressure (exerted upon the surfaces 8 and 9) from pushing the tools 4 and 5 in the direction of movement of the slab 1, by more than an insignificant amount. When this condition is attained, the forging action of the tools 4 and 5 is not necessarily accompanied by any axial push in either direction.

It would be possible to effect a substantial reduction of the slab thickness by repeated use of the simple forging tools illustrated in FIGURE 1, it being understood that the tools have a reciprocating movement and that the slab is advanced a predetermined distance between strokes. However, depending upon the reduction desired, the forging tools 4 and 5 are preferably configured as shown in FIGURE 2, to provide a series of flats generally correspondings to the flats 7 as above described, and a series of surfaces corresponding to the surface 9 in FIGURE 1. It will be noted that the extent of a second fiat 17 in the direction of the length of the slab is greater than the extent of the flat 7 and so on throughout the entire operating surface of the tools. Thus the fiat 27 in FIGURE 2 has a greater extent than the flat 17. This takes care of the elongation of the slab produced by its reduction in thickness; and it will be seen that there will be small cavities 12 left between the tools 4 and 5 and the surface of the slab when the tools on a succeeding stroke first engage the slab surface. These cavities do not become filled with the metal of the slab until approximately the end of the tool stroke. The slab 1 is thus given freedom to expand in the forward direction as well as in the backward direction when pressed by tool areas corresponding to area 8 of FIG. 1; and the tools 4 and 5 are prevented from skidding too far forwardly of the slab under the joint influence of the inclined tool faces 9, 19, etc.

Thus, depending upon the reduction desired, the forging tools exemplified by structures 4 and 5 in the several figures may be provided with a plurality of the step-wise configurations which have been described, so that each stroke of the tools against the slab will produce a reduction in thickness of substantially 5% to or more. The sequence of the step-wise operation of the tools is so chosen that the hump of metal which is formed ahead of each tool surface as the result of a forging action (see the left-hand step in FIGURE 2) will progress in a sequence of engagement steps of the pressing tools toward the part of the workpiece which is of decreased thickness, without creating surface defects.

The process of this invention further contemplates the powered movement of the tools 4 and 5 toward each other in the forging stroke which is not strictly parallel but is characterized by slight rocking motion so that, preferably, the tool surface constituting the last step in the reduction is the first surface to engage the slab 1. This initial engagement is rapidly followed by the engagement of the other surfaces in sequence. The maximum deformation pressure therefore, does not simultaneously occur at all of the tool surfaces. This is preferably accomplished by affixing the tool 5 in FIGURE 4 to a pitman 21 which in turn is actuated by an accentric element 23 on the powered shaft 22. In FIGURE 4 the tool 5 is shown as having a dovetail base engaged in an appropriately shaped groove in the pitman, but other modes of connection may be used. The shaft 22 may be rotated at any appropriate speed; but speeds between and 500 r.p.m. will generally be found suitable.

Since at the end of each stroke the foregoing tools will have moved slightly, in a direction lengthwise of the slab, due partly to the elongation of the slab by the forging action, and also due partly to the forward movement imposed upon the slab by outside instrumentalities such as feeding or reducing means, it is desired to provide for a fixed point of departure for each stroke. This may be accomplished as shown in FIGURE 4, by having the pitman 21 abut against an adjustable screw 36 or 36' held respectively by brackets 35 and 35'. During that part of the stroke when the tools are disengaged from the slab 41, springs 37 or 37 held respectively by

brackets

38 and 38, move the ends of the pitman structures against the screws as or 36' with a light pressure. At the same time the slab 41 will be free to move in the forward direction and hence is free to follow the speed imposed upon it by the feeding or reducing instrumentalities such as feed rolls 46 or planetary assemblies 47 shown in FIGURE 6.

In many cases it is desirable to modify the plastic reduction in areas adjacent to the edges of the slab 41 (see FIGURE 5) by providing forces or pressures directed away from the slab edges and toward the center of the slab. The purpose of this is to diminish or restrict lateral spreading of the unsupported edges of the slab 41. This may be accomplished by shaping the flat faces 7, 17, etc. of the tools 4 and 5 to incline them toward each other as shown at 11 and 12 in FIGURE 5 adjacent the slab edges. It has been found best to configure the tools so as to incline the areas 11 and 12 by about 3 to about 10 to the center plane of the slab, while engaging between about 5% and about 15% of the slab width, and depending upon the width of the slab being treated, in the first reduction step. The inclination of edge portions of the tools may be gradually increased for subsequent steps of the tool surfaces while the area of inclination is diminished, so that for the final tool step the angle of inclination may be as high as about 30, effective over only about 3% to about 5% of the slab width.

An added advantage of accomplishing what has just been described, is that the profile of the slab edges, indicated at 13 in FIGURE 5, lends itself better to subsequent reduction in the planetary mill, making it easier to avoid cracked edges in the finished strip (indicated at 54 in FIGURE 6) and to produce a reduced product with edges having a substantially square profile instead of a V profile.

In the use of the apparatus, the shaft 22 actuating the pitman for tool 5 and the corresponding shaft actuating the pitman for the tool 4 will be driven in synchronism with each other by an outside source of power, not shown. One way of accomplishing synchronisrn is by providing upper and lower shafts, one of which is shown at 24 in FIGURE 4, bearing pinions such as 25 engaging pinions on the drive shafts for the eccentrics which operate the pitman structures. One of these pinions is shown in FIGURE 4 at 27. A train of four gears, 28, 26, 26' and 28 interconnect shaft 24 and its upper counterpart. The upper drive shaft which is not shown in FIGURE 4, would turn in a clockwise fashion in that figure while its counterpart lower shaft 22 turns in a counterclockwise direction as indicated by the arrow. The shaft 22 and its upper counterpart are rotatably mounted in a frame 32 which is affixed to columns 31 of the housing of a subsequent feeding or reducing instrumentality. The tools 4 and 5 are so positioned that the central plane of the slab being forged will be aligned with the pass line of the feeding or reducing instrumentality. This can be accomplished by keys, one of which is indicated at 33 in FIG- URE 5, the keys being mounted on the columns 31. The forging means thus constitutes an independent unit which can be quickly mounted or removed from the mill housmg.

A number of advantages result from the structure above described. First, the relatively gentle initial engagement of the edge areas of the slab 41 is particularly valuable if cast slabs are being operated upon or if an endless supply of material, such as may be produced by a continuous casting process, is being treated. Such cast slabs or endless supplies ofmaterial, are particularly vulnerable to edge cracking if a heavy deformation is practiced in the vertical direction only.

Second, after the final reduction at the end of the last step, the edge areas of the slab will have been subjected to a greater deformation percentage-wise than the rest of the slab. This condition is particularly beneficial when it is desired to produce metal strips which can be cold rolled after the hot reduction without the necessity of edge trimming.

Third, the final cross-section of the forged slab is not characterized by vertical edges but rather by edge portions which have inclined or rounded corners and a slightly bulging edge face, as illustrated at 13 in FIG- URE 5. This cross-sectional shape is most favorable for subsequent reduction of the slab in a planetary mill, in that it reduces the incidence of cracked edges on hardto-roll materials.

Fourth, the extra forging action practiced at the edges of the slab produces greater heat, counteracting to some extent at least, the loss of heat at the slab edges due to radiation. Thus the slab edges are left at a slightly higher temperature.

FIGURE 6 illustrates one way in which the present invention may be employed in the production of strip material from molten metal. The index numeral 40 designates a continuous casting unit, having a ladle containing the molten metal, an intermediate tundish and crystallizing mold. These elements do not require specific description; but other forms of continuous casting apparatus may be employed. A continuous slab 41 is produced and is shown as following the curved path of a cooling roller bed 44.

When the slab 41 reaches a series of straightening rollers 6 42, it will be completely solidified but still in a red hot condition. It is preferably first passed through a heat equalizing furnace 43.

When the continuous supply of material emerges from the furnace, it may, and preferably is edge rolled by a grooved'roll edger 45 which feeds it into the forging instrumentality. The forging instrumentality has been diagrammatically indicated at 55 in FIGURE 6, and is preferably constructed as above described. The slab 41 is reduced by the forging operation to an intermediate thickness indicated at 51, suitable for further reduction in a planetary mill. It enters the planetary mill feed rolls 46, which may have some reducing effect, but in any event feed the slab into the planetary roll assemblies 47 of a mill 58 such as is described in U.S. Patent No. 2,710,550.

The intermediate gauge slab will be reduced in the planetary mill to a desired thickness (usually of sheet gauge). The strip is indicated at 53. It may subsequently be passed through a pair of planishing rolls 48 acting to convert it to finished strip 54 of the final desired gauge. The finished strip may be coiled on the drum 39 of a conventional coiler 56. As will be understood by the skilled worker in the art, when a coil of sufficient size is wound onto the drum 39, the strip may be cut by a flying shear 49, the coiler 56 may be turned to present its second drum 57 to the new leading end of the strip, the strip may be fed forwardly by pinch rolls 50 until it is engaged with the drum 57, and the winding of a new coil started without interruption. Meanwhile the finished coil may be removed from the drum 39.

FIGURES 7 and 8 show another embodiment of apparatus suitable for the practice of the present invention. In this embodiment a sequence of forging tools 60 to inclusive, is substituted on each side of the slab for the single-piece forging tools 4 and 5 which have been described above. One advantage of this arrangement lies in the fact that individual forging tools are easier to maintain and replace than the more elaborate individual tools 4 and 5. In the operation of the machine of FIGURES 7 and 8, the individual tools 60 to 65 inclusive, are advanced against the slab 41 in succession, so that by the time tool 65 has completed its working stroke, tool 60 is again engaged with the slab. In FIGURES 7 and 8 mechanical elements located below the slab are given primed index numerals, otherwise the same as the index numerals for corresponding elements located above the slab.

The individual forging tools illustrated in FIGURES 7 and 8 can be actuated in various ways by mechanical elements or fluid pressure elements. One way of actuating them is by the provision of multi-Wedge elements 66 and 66', there being one of these elements for each of the individual tools as will be evident from FIGURE 8. The multi-Wedge devices are reciprocated longitudinally as may be accomplished by providing connecting rods or pitman structures having surfaces "72 and 72', which are not rigidly connected with the multi-wedge structures but instead engage them through rollers or shafts 73 interposed between the surfaces 72, 72' and end portions of the multi-wedge devices. This construction permits a rocking motion of the pitman structures 71, 71', while the multiwedge structures 66, 66' follow a rectilinear path. Engagement between the respective end portions of the multiwedge structures and the surfaces 72, 72 (through the rollers 73, 73) is maintained by means of springs 74, 74'.

Driven

shafts

75, 75 are common to the various pitman structures. These shafts carry eccentrics 76, 76' upon which the several pitman structures are mounted by means of

bearings

77, 77 From what has been said above, it will now be evident that the various eccentrics 76, 76' (there being one for each multi-wedge element in the assembly) will be keyed to the shafts 75, 75' in such a way that the tools 60 to 65 inclusive will be actuated in. sequence. Also the eccentrics will be so arranged that opposed individual tools, such for example as tools 60 and 60', will be simultaneously actuated. I

The

multi-wedge members

66, 66 tools 69 to 65 and their primed counterparts, through

rollers

80 and 80. These rollers preferably have spherical faces, the multi-wedge members and thelap portions of the several forging tools having matching concavities. The rollers are mounted in cages 81, 81', there being one roller for each wedge shaped face portion of the multi-wedge members, and one roller cage for each forging tool. It will be evident from FIGURES 7 and 8 that the forging tools are pressed against the slab 41 by the action of the multi-Wedge members when these move to the left in FIGURE 7. The forging tools 60 to 65 and their primed counterparts are free to move in a direction longitudinally of the slab, but can return in the opposite direction when the tools are brought out of contact with the slab upon actuate the forging movement of the multi-wedge members to the right in FIGURE 7. To permit movement of the tools in the direction of the slab and to return them to their starting positions use may be made of elements analogous to the stop means 36, 36' and springs 37, 37 as previously set forth in connection with FIGURE 4. These have not been shown in FIGURES 7 and 8 for the sake of clarity. Also, the forging tools may be returned to positions out of con tact with the slab 41 by spring or other means which again have not been shown in FIGURES 7 and 8 for the sake of clarity.

The forging pressure of the tools during the working stroke may be taken up as follows; the multi-wedge members 66, 66' are mounted for sliding movement against platents 83, 83' by means of small rollers 82, 82' forming a roller bed. To adjust the depth of penetration of the forging tools into the slab 41, the effective positions of

platens

83, 83 may be carried by the movement of

Wedges

84, 84 which rest upon the members 85, 85'. These members in turn are supported by beams 86, 86' forming part of a housing for the forging apparatus as will be clear from FIGURE 7. The movement of the

wedges

84, 84 may be accomplished, and the wedges may be held in adjusted position by any suitable means known in the art, such as screws.

The upper and lower tool elements 60 to 65, and their primed counterparts, will be driven in succession as above explained, but in such synchronism that opposed forging tools will contact the slab 4-1 symmetrically and at the same time the working ends of the tools will be so configured that they perform the same series of step-wise reductions as has hereinabove been explained with respect to FIGURES l, 2 and 3. The various tools may have their working ends so configured as to produce the edge effects previously outlined in connection with FIGURE 5. The apparatus illustrated in FIGURES 7 and 8 is not designed to produce longitudinal movement of the slab excepting as the result of the elongation thereof. As a consequence extraneous means must be used in order to move the slab through the forging instrumental-ity. Such extraneous means may be the feed rolls 46 illustrated in FIGURES 4 and 6, but not shown in FIGURES 7 and 8.

FIGURES 9, 10, 11 and 12 show another embodiment of the invention. In these figures, as in those above described, numerals applied to elements located above the slab have been primed when applied to counterpart elements below the slab.

In the embodiment of FIGURES 9 to- 12, several pairs of forging tools such as the tool-

s

99, 99 are located in tool driving means having a power stroke which is not substantially normal to the surface of the slab, but on the contrary lies at a smaller angle in the rearward direction, such as an angle of about 20 to about 30. When the forging tools during the power stroke are pressed into the slab, the. result is not only a reduction in the thickness of the slab, but also the exertion of a forwardly directed force on the slab. Consequently the use of extraneous means to move the slab through the forging means is not necessary, and the forging means itself may be used as a positive feeding device for a subsequent reducing instrumentality, such as the planetary mill 58 partially indicated in FIGURE 10. Under these circumstances, the forging means is preferably located in a sub-frame 101 which is placed inside and bolted to the planetary mill housing indicated at 102.

There are various ways in which the forging tools may be actuated. One way, as shown in FIGURE involves the pro-vision of tool holders 87, 87' which are rockably joined to oscillating plates such as those shown at 103" in FIGURE 10. This connection may be effected by providing gs 105 in the members 103 and causing these pegs to enter holes in the ends of the tool holders. Such a mode of attachment will permit a rocking movement of the

tool holders

87, 87 during the power stroke,

but will help to return the tool holders to their original positions when out of contact with the slab. Springs indicated at 106, 106 in FIGURE 10 are connected between frame portions in the machine and the tool engaging heads of the

tool holders

87, 87. These springs assist in returning the tool holders to starting position after a power stroke, in maintaining the connection between the tool holders 87, 87' and the oscillating plates or platens 103, and act to preload the system.

The tool holders have a transversely rolling contact with the plates or platens 103 and these in turn have a transversely rolling contact with hardened steel inserts in platen member 104. The last mentioned platen members are oscillated by any suitable means. For example, wobbler rings 107 may be rotatively mounted upon bushings 108' which in turn are keyed on the parallel shafts 109 and 110. The positions of these two shafts are illustrated in FIGURE 12. They are disposed one on the right hand side and the other on the left hand side of the forging mean-s. They are rotated in synchronis-m with each other as may be accomplished by providing each of the shafts 109' and 110 with bevel gears 98', which are in mesh with bevel gears on a counter shaft 111', which is partially shown in FIG- URE 12. One of the last mentioned bevel gears is indicated at 97'.

The Wobbler rings 107' provide a skewing rotation in following the movement of the angular bushings 108', and this movement is divided into two components. There is first a component around a vertical axis so that the Wobbler rings 107 can oscillate about trunnions 112. These trunnions are located in fork arms shown at 113 and 114 in FIGURE 12. The fork arms form a part of the platen 103'.

The second component of the movement of the wobbler rings (which is a movement around the horizontal axis) is utilized for the actuation of the tool holders 87', and is transmitted to the oscillating plates 103' by means of the above mentioned arms 113, 114 which are rigidly connected to or are a part of the platen 104. The disposition of driving means, one at each end of the platen 104', assures complete parallelism in the operation of the tool holders 87, '87.

In FIGURE 10, three sets of the

tool holders

87, 87 with their corresponding forging tools are shown, although a greater or lesser number may be employed. The tool holders are driven as above described from the angular bushings 108 on the shafts 109 and 110. The tool holders preferably operate in succession so that the several bushings 108' will be attached to their shafts in a relationship of about to each other where three tool holders are used on each side of the slab. Since the slab will be reduced and elongated by the operation of the forging tools, departures from an exact angula-rity of 120 will be required. To accomplish this the angular bushings 108 are provided with toothed couplings, one of which is indicated at 121 in FIGURE 10 to provide for adjustment.

While FIGURES 9 to 12 inclusive show forging tools acting only upon the horizontal surfaces of the slab 41, additional sets of such tools and their operating instrumentalities may be provided to act upon the vertical surfaces of the slab. Such a duplication of devices has not been illustrated in the drawings for the sake of clarity. Where forging tools acting upon the vertical surfaces of the slab are provided, their action may either alternate with or occur simultaneously with the action of the illustrated tools and driving means. For example, forging tools engaging the vertical surfaces of the slab may, for example, be timed to occur with or immediately after every second stroke of the illustrated tools and tool holders.

The

tools

99, 99 follow the principles outlined in connection with FIGURE 4 above described, and the tools should be so actuated in sequence as to provide for a smooth flow of the metal.

The Wobbler rings 107' may be so arranged as to oscillate the plates or platens 103 substantially from a dead center position over a full incline to the left in FIGURE 10 and back again to dead center, for each rotation of the shafts 109 and 110. Alternately they may be arranged to oscillate the platens 103' (as shown in FIGURE 10), in such a fashion that each plate is moved from dead center to the left then back over dead center to the right, and finally to dead center again for each rotation of the driving shafts. Where this is done, each complete rotation of the driving shafts 109', 110 will cause each of the forging tools to be driven through two working strokes.

Where the forging means as in FIGURES 9 to 12. inclusive, not only reduce the thickness of the slab 41 but also act as a feeding means for the planetary mill 58 (avoiding the necessity for pinch roll feeding means such as are shown at 46 in FIGURE 6), it is evident that the action of the forging tools could be coordinated with the action of the planetary rolls 47, 47, and synchronized therewith. It is highly desirable that the precise moment when any given pair of planetary working rolls 47, 47' of the mill first engage the reduced slab 52 (i.e. when the angularity of movement of the working rolls is highest, with respect to the plane of the slab, and their backward thrust component is greatest) should coincide with the full penetration of the forging tools. This is because at the point of full penetration the forging tools can best resist the backward thrust of the mill without at the same time permitting the slab to skid between the planetary working rolls. For this purpose the drives of the planetary mill -8 are preferably synchronized by mechanical or other means with the drives of the forging instrumentality.

One of the last mentioned drives is illustrated diagram matically in FIGURE 12 by the coupling means 116, which will be understood as connected to a suitable prime mover. In this way the forging means and the planetary mill can be adjusted for the smoothest operation of the entire assembly.

It is advantageous in certain cases as shown in FIG- URE 9, to limit the penetration of the forging tools. This is done by providing the heads of the tool holders with pins 125, at each end. These pins first slide over surfaces 127 of members 126 affixed to the frame of the machine, and then slide along through surfaces of the same members, the last mentioned surfaces being parallel with the center plane of the slab. This arrangement limits the penetration of the forging tools into the slab while permitting them to urge the slab forwardly during the remainder of the forging stroke. The elements 126 also assist in conjunction with the springs 106' in returning the heads of the tool holders to their original positions at the end of each stroke.

Yet again, the devices marked generally 126, may be used to effect slight adjustment of the angles of the (forging tool holders. As shown in FIGURE 11, the member 126 can be attached to a slide 128 which is dovetailed on to the housing 101, and is adjustable in its longitudinal position 'by means of a screw 129. A movement of the platen 126 toward the left in FIGURE 9 will increase the inclination of the tool holders 87, 87' and vice versa. This makes it possible to increase or decrease the feeding distance accomplished by any pair of the forging tools during the working stroke.

The slides 128 are preferably provided with platens 117 having hardened inserts 118 which may be adjusted in height by means of shims 119 (seeFIGURE 10). If the slide 128 is moved to the right in that figure, the gap between the forging tools will close by a proportional amount, and vice versa.

The pins 120 at the ends of each forging tool holder may be clamped in brackets 122 (FIGURE 12) so that they may be readily replaced.

To provide a profile of the workpiece with edge inclinations, similar to those shown at 11 and 12 in FIG- URE 5, the respective forging

tools

99, 99 may be provided with tapered portions at their ends. Since in some operations the width of the slab 41 may change, it is possible to provide a tapered portion on one side only of a cooperating pair of the forging tools, and a tapered portion on the other side of the next pair of forging tools.

The tapered portions could be brought into proper relationship with edge portions of the slab by moving the forging tool holders 87, 87' laterally.

Modifications may be made in the invention 'without departing from the spirit of it.

The embodiments of the invention to which an exclusive property or privilege is claimed. are defined as follows:

1. A process of reducing the thickness of a metallic slab by a forging operation while the slab is at a temperature which imparts heat plasticity to it, which process comprises subjecting the faces of said slab to the action of at least one pair of pressing tools extending across the width of the slab, one pressing tool being located on each side thereof, energizing said tools so as to produce a reduction in the thickness of said slab by compression in a series of steps in each of which said slab is reduced in thickness by approximately 5% to 10% between tool surfaces having a slight negative incline with respect to the direction of elongation. of the slab, the said tool surfaces terminating in narrower surfaces positively inclined to the direction of elongation, whereby axial pressures are exerted upon said slab in opposite directions, and coordinating the said axial pressures to determine the position of the said slab at the conclusion of each of the said steps.

2. The process claimed in claim 1 wherein the said axial pressures are so coordinated that the position of the slab at the conclusion of each step remains the same excepting for the elongation thereof, and feeding the said slab forwardly into a new position between the said tools at the conclusion of each step.

3. The process claimed in claim 1 including the step of bringing said tools against said slab in a direction to cause said slab to move forwardly as a result of each such step.

4. The process claimed in claim 3 in which the forward movement of the said slab causes it to be fed into a planetary reducing instrumentality.

5. The process claimed in claim 3 wherein the said tools during each step are caused to move slightly in the direction of elongation of said slab.

6. The process claimed in claim 1 wherein the forging surfaces of the said tools are configured to provide a series of step-wise reductions in the slab, including the step of configuring the surfaces of said tools so that the surfaces which are slightly negatively inclined to the direction of elongation of said slab increase in breadth progressively in the direction of the elongation.

7. The process claimed in claim 6 wherein said tools are brought against the surfaces of said slab with a slight rocking motion so that the maximum deformation pressure is not simultaneously taken by all of the tool surfaces.

8. In apparatus for the purpose described, at least one pair of forging tools, said forging tools having a length to extend across the width of a hot slab, said forging tools having working faces configured to provide relatively broader areas negatively inclined to the direction of slab elongation and relatively narrower areas positively inclined to the direction of slab elongation and means for moving said tools simultaneously against a slab whereby to produce a reduction in the thickness thereof.

9. The structure claimed in claim 8 in which the forging faces of said tools are configured to produce upon each stroke a series of step-wise reductions in said slab, said tools each having a plurality of surfaces slightly negatively inclined toward the direction of elongation, which surfaces increase in breadth in the direction of elongation in proportion to the thickness of the slab produced by each such surface.

10. The structure claimed in claim 8 in which the forging faces of said tools are configured to produce upon each stroke a series of step-wise reductions in said slab, said tools each having a plurality of surfaces slightly negatively inclined toward the direction of elongation, which surfaces increase in breadth in the direction of elongation in proportion to the thickness of the slab produced by each such surface, and wherein means are provided to impart to the said tools a rocking motion during the forging stroke.

11. The structure claimed in claim 8 wherein said tools at their ends have an inclination toward each other whereby to reduce edge portions of the slab by a greater amount than the central portion thereof.

12. The structure claimed in claim 8 including a plurality of pairs of forging tools and means for actuating said forging tools in succession.

13. The structure claimed in claim 8 wherein said tools are respectively mounted on pitman structures engaging eccentrics on driven shafts, one such shaft being on each side of said slab.

14. The structure claimed in claim 8 wherein said tools are respectively mounted on pitman structures engaging eccentrics on driven shafts, one such shaft being on each side of said slab, end portions of said pitman structures being capable of a rocking motion, and being provided with stop means to limit motion in one direction axial of the slab and with resilient means for returning said pitman structures to a position against said stop means at the conclusion of an operating stroke.

15. In a continuous forging device for heat-plasticized slabs, a plurality of pairs of forging tools, one tool of each pair being located on each side of the slab, said tools being of a length to extend across said slab, and means for actuating said pairs of tools sequentially whereby to effect a reduction in the thickness of said slab, at least some of the said tools having at their ends an inclination toward the opposite tool of a pair thereof, which inclination results in a greater reduction in edge portions of the slab than at the center thereof.

16. The structure claimed in claim 15 in which said means for actuating said tools comprises multi-wedge members, a pair of driven shafts, eccentric means on said shaft, means reciprocated by said eccentric means and connections between said reciprocated elements and said multi-wedge members, there being one multi-Wedge member for each tool in the assembly, rollers interposed between said multi-wedge members and said tools whereby to move said tools upon reciprocation of said multiwedge members, a machine frame and means in said machine frame for adjustably backing said multi-wedge members.

17. The structure claimed in claim 16 in which said backing means includes a platen, said multi-wedge members being slidable with respect to said platen on rollers and wedge means for adjusting the position of said platen in said frame.

18. In a continuous forging device, a series of pairs of forging tools for reducing the thickness of a slab, tool holders for said tools, means for actuating said tool holders so as to bring said tools in pairs against said slab at an angle greater than a right angle as measured in the direction of elongation of said slab whereby said slab is both reduced in thickness and fed forwardly.

19. In a continuous forging device, a series of pairs of forging tools for reducing the thickness of a slab, tool holders for said tools, means for actuating said tool holders so as to bring said tools in pairs against said slab at an angle greater than a right angle as measured in the direction of elongation of said slab whereby said slab is both reduced in thickness and fed forwardly, and a planetary mill assembly attached to said forging device, said forging device acting both to reduce a slab to a thickness which can be accepted by said planetary mill and to feed the reduced slab forcibly into said planetary mill.

20. The structure claimed in claim 19 in which the actuating means for said tool holders cause said tools to act sequentially in pairs on said slab.

21. The structure claimed in claim Zil in which said tool holders have heads and including means for guiding said heads so as to bring the tools of each pair into contact with the slab at the desired angularity and then to travel with said slab in the direction of elongation for a short distance before leaving the surface thereof so that the feeding speed of said slab can be made uniform and so that the speed of feeding of said slab may be correlated with the rate of acceptance thereof by said planetary mill.

No references cited.

HARRISON L. HINSON, Primary Examiner.

Claims

1. A PROCESS OF REDUCING THE THICKNESS OF A METALLIC SLAB BY A FORGING OPERATION WHILE THE SLAB IS AT A TEMPERATURE WHICH IMPARTS HEAT PLASTICITY TO IT, WHICH PROCESS COMPRISES SUBJECTING THE FACES OF SAID SLAB TO THE ACTION OF AT LEAST ONE PAIR OF PRESSING TOOLS EXTENDING ACROSS THE WIDTH OF THE SLAB, ONE PRESSING TOOL BEING LOCATED ON EACH SIDE THEREOF, ENERGIZING SAID TOOLS SO AS TO PRODUCE A REDUCTION IN THE THICKNESS OF SAID SLAB BY COMPRESSION IN A SERIES OF STEPS IN EACH OF WHICH SAID SLAB IS REDUCED IN THICKNESS BY APPROXIMATELY 5% TO 10% BETWEEN TOOL SURFACES HAVING A SLIGHT NEGATIVE INCLINE WITH RESEPECT TO THE DIRECTION OF ELONGATION OF THE SLAB,THE SAID TOOL SURFACES TERMINATING IN NARROWER SURFACES POSITIVELY INCLINED TO THE DIRECTION OF ELONGATION, WHEREBY AXIAL PRESSURES ARE EXERTED UPON SAID SLAB IN OPPOSITE DIRECTIONS, AND COORDINATING THE SAID AXIAL PRESSURES TO DETERMINE THE POSITION OF THE SAID SLAB AT THE CONCLUSION OF EACH OF THE SAID STEPS.