US2789450A

US2789450A - Rolling mill

Info

Publication number: US2789450A
Application number: US335346A
Authority: US
Inventors: Properzi Ilario
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-02-05
Filing date: 1953-02-05
Publication date: 1957-04-23
Anticipated expiration: 1974-04-23
Also published as: FR1074735A

Description

I. PROPERZI ROLLING MILL April 23, 1957 7 Sheets-Sheet 1 Filed Feb.

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April 23, 1957 1. PROPERZI 0 ROLLING MILL Filed Feb. 5, 1953 7 Sheets-Sheet 7 NVENTORV United States Patent ROLLING MILL Ilario Properzi, Milan, Italy Application February 5, 1953, Serial No. 335,346

2 Claims. (CI. 80-36) The present invention relates generally to rolling mills for metal rods or the like, and more particularly to an improved rolling mill which comprises a train or series of aligned rolling units each contributing progressively to reduce the cross-section of metal stock introduced into the mill.

Rolling mills having a train of rolling units each with a pair of rolling members are known, but these have the disadvantage in that it is a simple matter for the metal stock being rolled to undergo undesired rotation from one rolling unit to the other which produces defects in the rolled product. The rotational tendencies of the stock have been overcome in the past by the use of three rolling members for each rolling unit. These rolling members in each unit are placed at angles of 120 to each other and exert a concentric pressure over the complete surface of the Wire and, by displacing the rolling members of successive units angularly by 60, the rod may be passed through the rolling mill from one unit to another without being subjected to rotational stresses so that the properties of the ultimate product are substantially improved.

Despite the undoubted advantages of using three rolling members in each unit with the units arranged in the aforedescribed manner, constructional difficulties have been encountered in providing a rolling mill in which a train of such units is utilized. One difiiculty is the fact that the drive shafts of successive rolling units must be placed alternately above and below the rolling axis due to 'the. fact that the rolling members of successive units are displaced 60 with respect to one another. Moreover, as a result of the alternate locations of successive drive. shafts, the rotational drive thereof must be alternately reversed to maintain the rolling in one direction.

Yet another difficulty is the fact that the rate of rotation of the rolling members of successive rolling units must be progressively increased because of the elong'ations in the rod due to the reductionof cross-section thereof as it passes from one unit to another. Theoretically the required rate of rotation of the successive rolling units is a function of the rolled cross-section produced thereby on the rolled rod. However, it has been found in practice that strict adherence to such theoretical rotational speed is not possible. The reason for this is that the theoretical values are subject to material variations when different types of metal stock are rolled and for different temperature conditions. Consequently, for satisfactory operation it is necessary that the rolling mill be capable of simple adjustment to accommodate different metals and for different temperature conditions. Unless such an adjustment is provided, the rolled rod undergoes excessive tensional and compressionat strains which result either in fracture or in unsatisfactory operation of the mill.

, It is an object of the present invention to provide an improved rolling mill in which the difiiculties and 2,789,450 Patented Apr. 23, 1957 "ice problems encountered in the art are overcome for all practical purposes.

7 A further object of the invention is to provide such an improved rolling mill which includes a series of rolling units in which the rolling members of such units are driven in a simple, efiicient and highly improved manner.

Yet another object of the invention is to provide such an improved rolling mill including a series of rolling units in which such units are readily adjustable so that the mill may accommodate difierent metals and operate under different temperature conditions, thereby increasing the flexibility of the mechanism.

Yet another object of the invention is to provide such an improved rolling mill which includes a series of individual rolling units which are so constructed and driven that the overall dimensions of the rolling mill are reduced to a practical minimum.

A still further object of the invention is to provide such an improved rolling mill which may be readily accommodated to produce rolled metal rod of a wide variety of diameters.

A feature of the invention is the provision of an improved rolling mill comprising a train of rolling units with drive shafts positioned alternately above and below the rolling axis, in which only one of a group of such units is directly driven and transmites rotational motion to other units in the group in the proper direction and at appropriate different speeds for each unit, by means of a simple replaceable pinion and gear arrangement. This provides an extremely simple, rugged and accessible assembly, and also allows the various rolling units to be placed in close proximity one with the other to decrease the overall dimensions of the rolling mill.

Another feature of the invention is the provision of an improved rolling mill which is constructed so that the individual rolling units constituting the mill may be expeditiously excluded from the train for cleaning purposes, or for enabling the metal stock to be withdrawn from the mill at any intermediate point when it is required to produce a rod of a cross-section which is larger than would bethe case were it to traverse the whole train.

Another feature of the invention is the provision of an improved rolling mill in which the rolling cross-section in each rolling unit may be conveniently adjusted to'accommodate different metals having difierent moduli of elasticity or to compensate for different temperature conditions.

The above and other features of the invention which are believed to be new are set forth with particularity in the appended claims. The invention itself, however, together with further objects and advantages thereof may best be understood by reference to the accompanying drawing in which:

Fig. 1 illustrates one type of rolling unit for incorporation into the rolling mill of the invention having its drive shaft positioned below the rolling axis,

Fig. 2 is a longitudinal section through the rolling unit illustrated in Fig. 1,

Fig. 3 is a cross-sectional view of a second type of rolling unit for incorporation into the rolling mill having its drive shaft located above the rolling axis,

Figs. 4 and 5 are detailed views of a portion of the rolling unit of Fig. 3.

- Fig. 6 is a front elevation of the complete rolling mill constructed in accordance with the invention and arranged on a common base,

- Fig. 7 is a plan view of the rolling mill shown in Fig. 6, Fig. 8 is a rear elevational view of the driving means for the rolling mill of Figs. 6 and 7,

Fig. 9 is a cross-sectional view taken along the line 9--9'of Fig. 8, i

the transmission mechanism for the various rotary spindles 35-37 and the engagement of these spindles with the drive shafts of rolling units 22-34, is shown in Fig. 7. As previously pointed out, the first group of spindles is driven from the main spindle 39 to which the toothed crown 62 and gear wheel 65 are rigidly connected, whereas the second group is driven from the main spindle 45 which has a similar toothed crown 64 and gear wheel 66 affixed thereto. The transmission mechanism for one group of spindles is shown in perspective in Fig. 10, it being understood that a similar arrangement is used for the other group. As previously noted, it is necessary that the various spindles of each group be rotated at difierent speeds, and also that successive spindles be rotated in alternate directions, this being achieved by the transmission mechanism of Fig. 10.

As previously pointed out, the main spindle 45 derives rotary motion from the main driving means directly through the toothed crown 64 rigidly connected thereto; Gear 66 is also rigidly connected to the main spindle and engages a gear 67, the latter being rotatably mounted on shaft 69 and rigidly secured to 'a further gear 68 of smaller diameter. Gear 68 meshes with a rotatably mounted reversing gear 70, the latter engaging a gear 71 fixed to spindle 44. In this manner, rotation at a reduced speed is imparted to spindle 44, which is positioned above the rolling axis, in a direction opposite to the rotation of spindle 45 below the rolling axis. It is to be noted that

gears

66, 70 and 71 are of equal diameter and have the same number of teeth, the reduction in rotary speed of spindle 44 with respect to thatof spindle 45 being determined solely by the ratio of the diameters and the number of teeth of

gears

67 and 68. This simple arrangement provides for high power transmission in a relatively small space.

Gear 70, in turn, transmits rotary motion to gear 75 on spindle 43 through a pair of

gears

72, 73 rotatably mounted on shaft 74, the larger diameter gear 72 engaging gear 70 and the smaller diameter gear 73 meshing with gear 75. In this manner, spindle 43 is rotated in the opposite direction to spindle 44 and with a decreased speed. In a similar fashion, rotation is transmitted from gear 75 to spindle 42 so that the latter spindle rotates in the opposite direction to that of spindle 43 and with a decreased speed relative thereto.

At the left-hand side of Fig. 10, gear 66 engages a gear 76 which, together with a gear 77 of larger diameter rigidly connected thereto, is rotatably mounted on a shaft 78. Gear 77 engages a rotatably mounted revers' ing gear 79 which, in turn, meshes with a gear 80 secured to spindle 46. In this manner, spindle 46 is rotated in a direction opposite to the rotation of spindle 45 and with increased speed relative thereto. Gear 79, likewise, drives a gear 81 rigidly secured to spindle 47 through a pair of atiixed rotatable gears 82 and 83, gear 83 being smaller than gear 82 so that spindle 47 rotates in a direction opposite to the rotation of spindle 46 and at an increased speed.

With the transmission described above, it can *be seen that spindles 4247 are rotated at progressively greater speeds and in alternately opposite directions. In the gear train, not only are the

gear wheels

66, 70, 71, 75, 79, 80, 81, etc., of the same diameter and have the same number of teeth; but all the gear pairs 67/68, 72/73, 76/77, 82/83, etc., are also identical and are merely inserted and alternately reversed in the transmission mechanism to the right and to the left of the main spindle 45, in accordance with the speed increase or speed reduction required. This arrangement not only greatly simplifies the transmission mechanism but provides for rapid and convenient interchanging of the elements for replacement purposes.

Since the transmission ratio of the various gears of Figs. 7 and is invariable, means is provided in the rolling mill for adjusting the cross-sectional area of the rolling pass defined by each rolling unit so that precise adjustment for difierent types of metal stock and for varying temperature conditions can be made. This adjustment is illustrated in Figs. 3, 4 and 5. As shown in these figures, drive shaft 17 is rotatably mounted in bearings in a bracket 84, the bracket being secured by

bolts

85 and 86 to the

sides

87 and 88 of the casing of the rolling unit. In this manner, the drive shaft 17 is rigidly held for rotation about a horizontal axis and is immovable with respect to that axis. Rolls 19 and 20, on the other hand, are rotatably mounted on shafts 89 and 90, the shafts being respectively supported in bearings in

brackets

91 and 92 which, in turn, are secured to the

sides

87 and 88 of the rolling unit by bolts 93 and 94 respectively passing therethrough.

As more clearly shown in Fig. 5, bolt 94 is mounted in the

sides

87 and 88 of the roller unit so that it can be readily shifted'towards or away from the rolling axis by means of

screws

95, 96 and 97, 98 threaded into these sides. Adjustment of

screws

95, 96 and 97, 98 moves bracket 91 and, therefore, roll 19 towards or away from the rolling center by a small amount to control the crosssectional area of the rolling pass defined by the rolling members. These minor displacements of bracket 91 are kept within the engagement 99 between previously described bevel pinions 0n drive shaft 17 and shaft 89. As shown in Fig. 4, bracket 91 is disposed in a guide 101 in side 87 and a similar guide in side 88 to insure that the displacement takes place parallel to the original position so that the shape of the rolling pass remains unchanged for variation in its cross-sectional area. It is desirable that a similar lateral shifting adjustment may be provided for bolt 93 of bracket 92 so that the same configuration can be maintained for the rolling pass as its dimensions are altered. In this manner, although the rolling speed of each rolling unit is invariable, the crosssectional area of each rolling pass may be adjusted to accommodate a wide variety of metals and difierent temperature conditions.

As previously pointed out, the rolling mill of the present invention also has the feature in that individual rolling units may be excluded from the rolling train for cleaning purposes or when the rolling requirements dictate a lesser number of rolling units. This feature is more clearly shown in Fig. 11 and, as illustrated in this figure, each rolling unit is mounted on base 112 by means of a threaded rod 108 which is secured to the base at its lefthand end. Rod 108 has a sleeve 106 coaxial therewith, the latter having internal threads engaging the threads on the rod and the sleeve being secured to a rolling unit, here designated as 110. Sleeve 106 has a squared end 107 which may be turned by means of a key applied thereto, and rotation of sleeve 106 causes the entire rolling unit to move to the right of the drawing with its splined drive shaft 4 disengaging its corresponding rotary spindle 114, the latter being rotatably mounted on the

upstanding bracket portion

111 and 113 of the base in the manner previously described and having an internally toothed socket. In this manner, by rotating sleeve 106, the rolling unit may be moved along sliding path 109 away from the rolling axis of the rolling mill and into an inoperative position. When it is desired again to place rolling unit 110 into an operative position, it is merely necessary to rotate sleeve 106 in the opposite direction and retract the unit.

The present invention provides, therefore, an improved rolling mill which is constructed to provide a relatively large number of rolling passes in a relatively small space and which incorporates a unique driving arrangement in which the rolling passes are arranged in driving groups so that the relatively large number of such units may be driven all with high power. It is of course to be understood, that when an additional number of passes is required, further groups may be provided. The invention also provides a rolling mill in which the cross-sectional iarjeassofrithesvarioussrolling,;passes-;may:be adjusted: for different conditions inaa simple and. convenientmanner,

succession ofirollingaunits:supported on .said.base struc- ..ture,.each including three'rollingm'embers angularlyspaced with respect to one another 'saidrollingzmerrrbersof-successivezoneszof said .units being angularly-displaced :from ronernnit to ithenextiand defining-ta series of rolling passes spacedtalongarolling axis,'-.said rolling unitsbeingmoveblei horizontally-on said ibasel along-sanl axis. transverse ion-said: rollingeaxis, alfirstrgroupr-of:drivesh-afts fora firstr. group :of' :said' rolling ."units respectively-:. extending along horizontal axes :perpen'dicular :totsaidrrolling axis zandaabove z said' rolling axis, .a second ..group of drive :shafts for :a see'nodigroup rofwsaidrolling .units'irespecti-vely zextendingalong horizontal axes perpendicular .to

saidrrolling :axis and; below rsaid rolling axis, said-"shafts Loft-said. rolling units being positionedinalternationialong saidszrollingz axis. and..said drivessh'afts :of said first and second. groups ibeingrotatable .in opposite directionsto drive. :said rolling units, with. said shaft having. splined extremities, a1.first .groupziof spindleszrotatably mounted nnssaidtbasefin respective alignmentwith said drive shafts :ohonemf;saidzgroups,.a second-group of spindles interposed flwith'ithe spindles ofsaid first .group in respective alignment .Withsaid :drive shafts :of the :other' of said groups;rsaidvspindies having rsplined socket 'portion for engagingtta correspondingxone of said splined shafts, a adnivingmiechanism for imparting rotational motion to one of said spindles, a first series of 'gearwheels -respec- -tivelyeaflixedto said spindles-of said first :group, a second series'sofsgear wheels arespectively afiixed to said' spind1cst1of ;said:second.1 group, a-series of reversing gear :wlreels rotatablyniounted on-said base .in respective em gagemenbwithsaiti'igear Wheels soft said. first series, taz'series of ilike pairszofs coaxial mutually: affixed; gear Wheels 10f unequal A diameters r rotatably ."monnted on :said base respectively interposed :between said reversing -gear Wheels and said .-,-gear1-wheels: .of said second series, with? one gear wheel of each-of said pairs engaging a corresponding'one of said reversingsgear wheels and -with-.the other v gear whee1 of. each. of 'said pairs engaging .a corresponding one oftsaidggear' wheels of; said second series, a first elongated threaded member-.monnted.-.on saidbase adjacent each said movable rolling. unitzandextending across said'rolling axis and a second elongatedthreaded member mounted onsaidnr'olling uriitincoaxial and'threaded relation with .said. firstt-threaded member, so -:that rotation -.of one .said :threaded member-s imparts individual. horizontal movement to said movable. rolling unit transverse .to said rolling axis.:between .an operative. position .inwhich said splined extremity of :the drive shaft-thereof engages-said socket:andaninoperative position. in which the. drive shaft of .said movable rollingiiintisdisengaged from said socket andsaidmovableunit .is'displaced entirely frorn said r011- .ing axis.

.2. .A.machine--as.defined inclaim 1 wherein saidrolling members.o..said..r0lling units aremountedon shafts, means operativelyconnected-to atleast one-of said shafts to adjusttherblling member toand away from said rollingaxis.

. References" Cited in thei-ileofthis patent UNITED STATES- PATENTS 287,008 Daniels Oct. 23, 1883 332,572 Tucker "Dec. 15, 1885 351,841 Lenox "Nov. 2, 1886 3883389 Bansen Aug.'28, 1888 433,286 Hanks July 29, 1890 439.;878 Kellogg -Nov. 4, 1890 455,621 Hicks July 7, 1891 518,608 Kent Apr. 24, 1894 616,092 Eynon Dec. 20, 1898 1,930,698 "Stie'fel Oct. 17, 1933 I 2;003,551 -Nygren June 4, 1935 2,053,694 'Buchels Sept. 8, 1936