US3462004A - Cooling bed construction - Google Patents

Description

y w. J. Hlm. COOLING yBED CONSTRUCTION `2 sheets-'sien 1 Filed June 9. 19,67

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Il l ll INVENTOR WILLIAM J. H| LL ATTORNEYS COOLING BED f COSTRUCTION 'iled June 9, 1967 2 lSheets-Sheet 2l v mn/Erv'rcm.l WILLIAM J.Hn l.

La mufd ATTORNEYS@ 3,462,004 COOLING BED CONSTRUCTION William J. Hill, Holden, Mass., assigner to Morgan Construction Company, Worcester, Mass., a corporation of Massachusetts y Filed June 9, 1967, Ser. No. 644,893 Int. Cl. B65g 25/04 U.S. Cl. 198-219 4 Claims ABSTRACT F THE DISCLOSURE This invention shows a cooling bed for use in a merchant or bar mill made in a manner permitting the bed to be any desired width and free of the mechanical complications that are present when attempts are made to widen known constructions.

which are connected to and moved by tension members affixed to crankpins on the eccentrics. p l The construction permits the overhang of the transfer racks to be held to a length commensurate with good mechanicaldesign that minimizes overloading of the cantilevercd ends.

CROSS REFERENCES TO RELATED APPLICATION The application of Myles Morgan Ser. No. 535,459 now Patent No. 3,324,992, assigned to Morgan Construction Company, the assigneey of this present application, illustrates some of the construction shown herein, but the claims therein are to other features.

Y BRIEF SUMMARY OF THE INVENTION In a cooling bed used in a merchant or bar mill, it is essential that there be adequate time to permit the red hot product placed thereon from the run-on table to cool to proper temperature for the next handling operation. The elongated products produced by the mill may vary widely in cross section and volume per unit of length. .If of large cross section, the number of pieces kicked off the run-on rollers onto the cooling bed will be fewer per'minute than in the case of small cross section product. Since the transfer rack of the cooling bed operates in a fixed time vcycle regardless of product size to move the produce one notch each time a length is kicked off, it follows that the small cross section product will reach the far side of the cooling bed in less time than the large cross section product.

Thus, as mill speeds have increased, to meet the coolf ing requirements of some of the products delivered at high speed, it has been necessary to widen the cooling bed United Statesi Patent() 3,462,004 Patented Aug. 19, 1969 The present invention overcomes completely this limitation of width. Now the bed may be any width with the ICO , vertical supports for the transfer racks placed at the considerably beyond the widths for the more slowly arrivfield, there is a practical limit to the extent the cool and y hot side eccentric actuated supports may be spread. Thus as conventionally supported beds are widened, excessive overhang occurs particularly on the hot side. This is undesirable structurally.

optimum design positions. This result is achieved by using only two eccentrics which actuate the two supports' on' the cool side and then through the use of tension members attached to crankpins on the two eccentrics, 'bell' cranks which carry the hot side supports in pivoted relation are rocked back and forth to produce the required up and down motion of the hot side of the transfer racks while the eccentrics are producing the required orbital motion of the entire unit. This is possible because of the rigid connection of the cool side supports with the transfer racks and the pivoted connection of the hot side supports with both the bell cranks and the transfer racks.

The present construction utilizes tension members reaching from the crankpins of the eccentrics to the bell cranks wherever located. The transfer rack supports carried by the bell cranks are of course in compression only and may be struts of various forms, e.g., tubes, I-beams, channels. The bearings at the upper and lower ends of the struts may be of a simple nature since there is very little relative movement. The higher temperature at the hot side is of no consequence. The overhang of the transfer racks at the hot side can be designed to carry the heaviest product of the mill without overstressing and without the tendency to overturn that is found in current constructions with a long overhang.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a side elevation of a cooling bed showing the invention. l IFIG. 2 is an elevation taken on the line 2-2 of FIG. l. FIG. 3 is an elevation taken on the line 3-3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring iirst to FIG. l of the drawings, there is shown in elevation a general view of a cooling bed incorporating the present invention. The upper part of the structure is conventional. The hot rolled product indicated at 2 is delivered from the mill to the run-off table 4. The accelerating rollers 6 operated in conventional manner by motor y8 carry the product 2 to proper position adjacent the cooling bed generally indicated at 10. Kick-off arms 12 function in timed relation with the arrival of the product 2 to' kick the still moving product oif rollers 6 into the rstnotch of the fixed rack 14 of the cooling bed. In this notch, the product indicated at 2 skids to a halt.

In accord with conventional cooling bed practice, the movable transfer rack generally referred to at 16 is then caused to function, moving in an orbital path as indicated by the circular dotted lines 18 and 19 to pick up the now stationary product 2' and move it forward to the next notch 'on the fixed rackat 2", This movement opens up theirst notch on the fixed rack 14 so that the next length of product 2 arriving on the run-on rolls 6 may be kicked o by arms 12 into the now open rst notch.

In this way, the hot product progresses across the cooling bed notch by notch losing temperature enroute until it is finally removed from the last notch of the fixed rack to be positioned first on the aligning rolls 20'and thence carried by the shuie bars 22 to the delivery table (not shown). n

Since the produce 2 coming from the mill may be of diifering cross-sectional dimensions according to the product then being rolled, it is customary to make the notches in the fixed and movable transfer racks 14 and 16 large enough to accommodate the largest size of product that the mill is capable of producing. When small sized product is :risalita being produced, the lengths will of course arrive at the run-on table in faster succession than when larger product is being produced. Thus the total cooling time available for a small cross-sectional product to cross the cooling bed is generally less than the time available for a large product to cross the cooling bed. However, the cooling rate is a factor of the surface area as well as volume per unit length. Thus the cooling bed must be wide enough to cool to a satisfactory temperature all of the various mill products regardless of the time cycle of the transfer racks for particular products. These limitations are understood by those skilled in the art.

A few figures, however, might be given to point up the problem. For example, in rolling bar, the bar might be delivered from the finishing rolls at 3000 feet per minute. After shearing to the desired length, the bar must be accelerated about 15% by the run-on rolls to provide the necessary gap between its tail end and the leading end of the following part.

After being kicked onto the first notch of the fixed rack of the cooling bed, and skidding to a halt thereon, the transfer rack is automatically actuated to advance the bar regardless of its cross-sectional size one notch in about six seconds. The waiting interval before the arrival of the next bar in the first notch varies according to the product delivery speed, but for "e's" bar may be another six seconds so that the total time in each notch would be l2 seconds for 3% bar.

The total cycle time for larger long length products delivered at slower speeds would be greater. In all cases, however, the total time on the cooling bed should permit the bar to cool to a temperature not greater than 800 F. and preferably nearer 500 F. In cases where the bars are to be straightened immediately on leaving the cooling bed, a temperature of about 350 F. is desirable, else the bars may not retain their straightened character.

The foregoing facts thus present a design problem as to the bed dimensions. Beds have been made as long as 420 feet, comprised of 30 foot section, all of which must function simultaneously to cause the step by step advance of bars. The bed width and length must be based on cooling rates of the various products considered in relation t tonnage and total transfer time cycle. Even though space in the mill is limited, the cooling bed must be widened to meet increasing cooling requirements. This means then that as the bed is widened the supports therefore must be spread farther apart so that the receiving end of the movable transfer rack will not be unduly cantilevered outwardly from the hot side supports.

According to the previous practice both the hot side and cool side supports of the cooling bed have been actuated by individual eccentrics driven from a common source of power in the form of a drive shaft running along the cool side. To drive the hot side eccentrics necessitated the use of expensive gearing and correspondingly expensive bearing structures. The advantage of the present construction which is about to be described makes it possible for the hot side supports to be located at any distance from the cool side supports without affecting in any way the conventional and required orbital movement of the movable transfer rack 16 and at the same time to eliminate much of the cost of present actuating means.

The construction that makes this result possible will now be described. The movable transfer rack 16 as can be seen from FIGS. l, 2 and 3 comprises a multiplicity of parallel notched members 24 each of which may be mounted on longitudinally spaced supports 26. These supports in turn may rest on a pair of spaced longitudinally extending beams 28 and 30. These beams, ordinarily 30 feet long, constitute together with the racks 24, one movable section of the cooling bed which may be of any required length according to the divided length of the product being produced. All sections operate in synchronism so that the product to be cooled is transferred from one side of the cooling bed to the other by the simultaneous orbital motion of the movable transfer racks which lift the product out of one notch of the fixed racks and deposit it in the next notch of the fixed rack sections.

The longitudinal beams 28 and 30 ordinarily will be connected at spaced points by crosswise extending girders 32 and 34. The beams 28 and 30 and girders 32 and 34 constitute a horizontal rigid supporting frame for the parallel movable transfer rack elements 24.

The frame is supported at'the cool side by two vertical struts 36 and 38 and at the hot side by two vertical struts 40 and 42. Each of the struts 36 and 38 as can be seen in FIG. l is of a braced character having a diagonal member 44 and an upper horizontal member 46 of such length as to render the frame and strut when fastened together completely rigid. Thus the horizontal rigid supporting frame will be maintained at right angles to struts 36 and 38.

The hot side of the frame is mounted in a different manner on the struts 40 and 42. Each of these struts has at its upper end a fork 48 receiving therebetween an ear 50 through which extends a pivot 52. The struts 40 and 42 are normally in compression and may take any convenient form. The lower end of each strut 40 and 42 is similar to the upper end, there being a pair of ears 54 which straddle the horizontal arm 56 of a bell crank 58. The ears 54 and arm 56 are connected in pivotal relationship by the pivot 60. The bell crank is pivoted at 62 and the upper arm 59 of the bell crank is connected by a pivot 64 to the straddling ears 66 of a tension member 68.

As shown in FIG. 3, there is conventional carrier bracing between cool sides struts 36 and 38 and the frame. Such bracing is shown in the form of the diagonals 69 secured to a longitudinal underbeam 70 running between the upper ends of struts 36 and 38. Other cross bracing at the hot side running between the hot side struts 40 and 42 is shown in FIG. 2, in which the braces are numbered 71 and connected at the upper and lower ends of the struts and together in the center by means of a plate 72. This bracing of course is only representative and may take any convenient form so long as it is adequate to prevent the transfer racks 24 from shfting their position intermediate the fixed racks 14.

The actuating mechanism for the structure heretofore described will now be explained. A drive shaft 73 extends the entire length of the cooling bed, that is, for the full length of the several 30 foot sections. When the drive shaft and related mechanismsl are actuated, all of the transfer racks 24 of the cooling bed will be simultaneously cycled so that a work piece of any length received from the run-on rolls will be transferred step by step across the bed.

Shaft 73 through conventional gears located in the housing of gear reduction unit 74 drives eccentric shaft 75. As can be seen in FIGS. 1 and 3, eccentric shaft 7S extends from support strut 36 to strut 38 and has on its ends a pair of eccentrics 76. These eccentrics support the struts 36 and 38 and are held thereon by yoke assemblies 78. Thus when drive shaft 73 is actuated, eccentrics 76 are rotated one full revolution and the struts 36 and 38 are moved correspondingly in orbital fashion.

Each eccentric 76 has extending outwardly from its outer face a crankpin 80. This crankpin carries thereon a boss 82 on the end of tension members 68. Crankpin is 90 out of phase and leading eccentric 76 so that when eccentric 76 has rotated from its lowerpost position to its uppermost position, crankpin 80 will have moved from a maximum position at the left to the maximum position at the right. In so moving, the bell crank 58 will be swung to the right a sufficient distance to cause the hot side struts 40 and 42 to move upwardly the same distance and at substantially the same rate that the cool side struts 36 and 38 will have been moved upwardly by eccentric 76. r

While the bell crank 58 is only responsible for up and clown movement of the struts 40 and 42, the rigid connection of struts 36 and 38 with the frame compels the upper end of struts 40 and 42 at the pivot 52 to follow susbtantially the same orbital movement as that of the struts 36 and 38.

It will now be appreciated from the foregoing explanation that the distance between the cool side struts 36 and 38 and the hot side struts 40 and 42 may be any distance called for by good design without involving'the correspondingly greater and greater expenses required by conventional practice in which both the cool side and hot side struts are mounted on identical sets of eccentrics gear driven from the common drive shaft. This is so because the member 68 is nothing but a simple tension member of any required length. Preferably, member'68 wouldA be in the form of a rigid steel tube of suitable length and strength.

In summary, the required orbital motion of the transfer rack is produced in each section of the cooling bed through the use of only two eccentrics acting directly on the cool side struts extending upwardly therefrom to support rigidly the frame at a structurally proper position. These eccentrics through associated crankpins actuate the two hot side struts through the use of simple tension members which may be of any length depending upon the selected locations of the hot side struts. The hot side struts may be placed close enough to the hot ends of the movable transfer bars so that even when the cantilevered ends are initially loaded with the heaviest product coming from the mill the cantilevered ends of the transfer rack members will not be overloaded and there will be no tendency for the movable transfer rack to upset or sag. In other words, the present construction lends itself to the design of a transfer rack of any width that will readily support all loading that will ever be imparted to it and at the same time the means for imparting the up and down movement to the lower ends of the hot side struts and the orbital movement to the top ends of the hot side struts will be more economical initially to install and thereafter to maintain.

I claim:

1. In a cooling bed a plurality of parallel transfer racks supported on at least two spaced cross beams,`

girders parallel to said transfer racks rigidly connected to said beams thereby to form a horizontal rack supporting frame,

said frame at the cool side supported by vertical struts rigidly xed to said frame, said cool side struts supported by rotatable eccentrics to impart orbital motion thereto,

said frame at the hot side supported by vertical struts each pivoted to the frame at the upper end and pivoted to a lever at the lower end,

and means including a tension member actuated by rotation of said eccentrics for swinging said lever up and down to move said hot side struts up and down in synchronized relation with the up and down movement of said cool side struts.

2. Means for supporting and actuating the transfer rack members of a cooling bed comprising a crankshaft, means for periodically rotating said shaft through 360, eccentrics on the ends of said shaft, vertical struts mounted on said eccentrics on the cool side of said bed, two mountings spaced from said eccentrics in the direction of the hot side of said cooling bed, a bell crank pivotally carried by each said mounting with one arm generally horizontal and the other generally vertical, vertical struts pivotally connected to the generally horizontal bell crank arms, a horizontal frame with spaced parallel transfer rack members thereon mounted on said four vertical struts, said frame rigidly secured to said cool side struts and pivotally secured to the upper ends of said hot side struts, a crank pin on each eccentric 90 out of phase therewith, and tension members connecting said crank pins with the generally vertical arms of said bell cranks, whereby upon rotation of said eccentrics said bell cranks will provide the vertical move-ment of the hot end of said transfer racks and the eccentrics will provide the vertical movement of the cool end of said transfer racks and horizontal movement of the entire rack.

3. Means for creating conventional orbital movement of a transfer rack of a cooling bed in which the cool and hot side supports are widely spaced, said means comprising two spaced eccentrics on a common shaft, two vertical struts mounted on said eccentrics and rigidly xed to said transfer rack on the cool side, two vertical struts on the hot side in substantial alignment with the cool si-de struts and each pivotally afxed at the lo'wer end to means that is movable up and down and each pivotally affixed at the upper end to said transfer rack, tension members connected to crankpins on said eccentrics and to said movable up and down means for actuating the latter, whereby rotation of said eccentrics will cause orbital movement of said cool side struts `and will cause corresponding up and down movement of said movable up and down means and the said hot side struts, the movements of said cool and hot side struts resulting in orbital movement of said transfer rack.

4. Supporting and actuating structure for the movable transfer rack of a cooling bed, said structure comprising two spaced eccentrics mounted on the ends of a common shaft and driven by gearing from a power source,

each eccentric having a crankpin out of phase with the throw of said eccentric,

a vertical strut mounted on each eccentric,

two bell cranks substantially aligned with said eccentrics and two vertical struts each pivotally mounted on one arm of one of said bell cranks,

a pair of vertical rigid braced struts supported by and movable in accord with rotation of said eccentrics,

a crankpin on each said eccentric,

the throw of said eccentric and crankpin being equal,

the center of the crankpin and center of the eccentric being disposed at 90 to each other with respect to the center of said crank shaft,

two other mountings on said base spaced from the eccentrics a distance equal to at least one half the length of said transfer racks,

each mounting carrying a bell crank pivotally mountted thereon, one arm of each bell crank connected by a tension member with one of said crankpins,

the other arm of said bell crank carrying in pivoted relation thereto Van upwardly extending supporting strut,

a horizontally extending frame supported by said two braced struts and by said supporting struts mounted on said bell cranks,

a connecting rod between each crank pin and the other arm of the aligned bell crank,

a rigid transfer rack supporting frame carried by said struts, said frame rigidly fixed to said eccentric supported struts and pivotally connected to the upper ends of said pivotally mounted struts,

whereby rotation of said eccentrics will cause said frame to move in an orbital path determined by the eccentric throw and the pivoted strut will have orbital movement at its upper end and up and down generally rectilinear movement of its lower end.

References Cited UNITED STATES PATENTS 5/1915 George -198-219 6/1967 Morgan 198-219 FOREIGN PATENTS 6/ 1960 Great Britain.

UNITED STATES PATENT FFICE CERTIFICATE oF CORRECTION Patent No. 3,462,004 August 19, 1969 William J. Hill It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the specification, Column 6, Claim 4, the material commencing in line 35 and ending in line 53 should be omitted s( that Claim 4 in its entirety should read as follows:

4. Supporting and actuating structure for the movable transfer rack of a cooling bed, said structure comprising two spaced eccentrics mounted on the ends of a common shaft and driven by gearing from a power source,

each eccentric having a crankpin 90 out of phase with the throw of said eccentric,

a vertical strut mounted on each eccentric,

two bell cranks substantially aligned with said eccencentrics and two vertical struts each pivotally mounted on one arm of one of `said bell cranks,

a connecting rod between each crank pin and the other arm of the aligned bell crank,

a rigid transfer rack supporting frame carried by said struts, said frame rigidly fixed to said eccentric supported struts and pivotally connected to the upper ends of said pivotally mounted struift's whereby rotation of said eccentrics will cause said frame to move in an orbital path determined by the eccentric throw and the pivoted strut will have orbital movement at its upper end and up and down generally rectilinear movement of its lower end.

Signed and sealed this 28th day of April 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents

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