US1594420A - Rolling mill - Google Patents

Description

Aug. 3 1926. I 1,594,420

J. s. LOCHHEAD ET AL ROLLING MILL Filed May 10, 1924 3 Sheets-Sheet 1 n FIG-.1.

Aug. 3 1926.

J. S. LOCHHEAD ET AL ROLLING MILL Filed May 10,

1924 s Sheets-Sheet 2 WITNESSES 0 2 s t 5 & w. w a. A & I. p

ROLLING MILL Flled May 10 Fll3.]]I.

J. S. LOCHHEAD ET AL Aug. 3 1926.

II ZVTOIQS 904m M WITNESSES Patented Aug. 3, 19 26.

' 1,594,420 PATENT OFFICE.

' JAMES S. LOCHHEAD AND WARREN WORTHINGTQN, F PITTSBURGH, PENNSYLVANIA.

ROLLING mun.

Application filed May 10,

rolling mills, and while it is not necessarily a so limited, we shall show and describe it in application to a rolling mill of which the component rolls are grooved in order to impose upon the rolled articles a particular shape in transverse section.

Fig. I of the accompanying drawing is a view partly in vertical and medial section and partly in side elevation of a rolling mill in which our invention is embodie Fig. II is a view of the same mill partly in end elevation, partly in transverse section. The plane of section of Fig. I is in Fig. II indicated by a dotted line II, and the plane of section of FigrII is in Fig. I indicated at II-II. Fig. III is a view in vertical section, on the plane indicated at III- III, Fig. I, and illustrating a modification.

The rolls of this mill which form the pass in which rolling is effected are indifl cated at 1. They are, as will be seen, grooved rolls. with half-round grooves and they co-operate to roll round bars. A dif ficulty commonly experienced in mills of thisnature for rolling such articles is the difficulty of maintaining the two rolls which constitute the roll-pass under all conditions and circumstances of rolling, in substantially exact corresponding position, to the end. that the rolled articles' shall, within permissible limits, be accurately round in cross-section. In the course of the operation of mills of this sort as commonly con- .structed, variations in the relative positions of the companion rolls occur, and these variations become so great in magnitude as to result in an imperfect and unsatisfactory product. These variations spring from the fact that as mills ordinarily are constructed, the rolls are held in alignment by means of two end-thrust collars upon each roll: These end-thrust collars are difiicult to lubricate, the areas of their bearing upon the roll bodies are relatively small, grit and scale are prone to find their way between the surfaces of the bearings; and these cir cumstances, taken in connection with-the fact that the rolls rotate at high speed, re-- sult in the mal-alignment alluded to, with results, as has been said, which are liable to be unsatisfactory, y

Our invention lies in recognizing the general tendency in the rolls of a' rolling mill to shift longitudinally, and in providmg that the tendency to shift, always 1924. Serial No. 712,203. 7

present, instead of being irregular in its occurrence and uncertain in its value, shall be ordered: specific provision is made, notv to diminish it, but to magnify it and make it, certain. Then, additionally, means are provided for resisting the tendency to shift,

to the end that the positions of. the rolls, both absolutely and relatively, may at all times be under control; We further provide that the means last named, that'is to say, the means for resisting the .shift, shall be adjustable.

not merely means for preventing the roll shift, but means which, allowing roll shift,

Thus our invention involves shall control roll shift and limit it to such an extent as to insure proper alignment, and no more. In other words, both of the rolls of the mill in which our invention is emq bodied are, while under the strain of the rolling operation, subject to a ,tendency to shift in a common direction, and while so subjected to a shifting tendency,ithey are at a 'certain point positively restrained against further shifting. Turning from this general characterization to the specific construction illustrated in the drawings, the two rolls, 1, 1, are provided with tapered necks, 2, 2, and are carried in bearings 3, 3, which are-correspondingly tapered. These tapered necks with correspondingly tapered bearings may be provided at one end of the mill only, but preferably they are provided at both ends, as is clearly'ind'icated in the drawings. If provided at both ends, the arrangement will, as shown in'Fig. Ibe that the taper shall at both ends of each roll, slope in the same direction. In the employment of the invention as we here have worked it out, the taper of the necks of the two rolls is in the .same direction, and that is the arrangement which we preferably employ, if only for the sake of simplicity in the general arrangement of the mill. J

Havin thus far disclosed our invention in its speci c embodiment, we pause to remark, that, with a mill so constructed, when the rolling operation is in progress, the strains of rolling which tend to separate the rollsthe forces of rolling are resolved by the bearingof the obl uesurfaces of the bodies one from another,- express themselves in a 2, 3, one upon another, and the horizontal component of this resolution of'forces tends to shift the rolls from right to left.

Opposite the ends bf the rolls, andspecificallyopposite the ends towards WhlCll the rolls tend to move, we arrange thrustbearings 4. The specific construction of these thrust-bearings is not important to our invention. Suflice it to say that as here shown they are of familiar type, consistmg of superposed layers of different material, properly lubricated, the whole, of course, being suitably backed. We preferably also make these thrust-bearings adjustable, as -by the set-screws 5.

It will immediately be perceived that, by the provision of these tapered necks for the rolls with their correspondingly tapered bearings and with the consequent tendency I which shall positively bearing blocks 3,

to a longitudinal shifting of the rolls, and byfthe further provision of thrusbbearmgs arranged to resist such shifting, we can so control the position of the rolls minutely as to bring them accurately to. alignment. Furthermore, throughout all the progress of the rolling operation, to the extent that ten dency to.-mal-alignment develops, we can without --disturbance of} the assembly, and

without disturbance of mill operation, and in most effective manner, reestablish the desired alignment.

Inthe foregoing description we have dwelt particularly upon'the tendency of the rollsxprovided 'witlr tapered necks when under the strain of rolling, to shift in one direction, the direction, namely, from right to left as viewed in Fig. I.

We now.v further remark that, although the Vertical strains of rolling exerted upon the oblique bearing surfaces tend to produce displacement of the rolls in the direction just indicated, there are in practical operation and under working conditions, strains which are not truly vertical and .stra1ns which may tend in the opposite direction. These oppositely tending strains may be derived from the particular shape of the ma terial itself or from the changes in shape of the roll body itself under wear. Our invention contemplates combining with the features already described other features resist displacement of the roll bodies in left-to-ri ht direction '(With reference to Fig. I). e here refer particularly to Fig. III, .where a permissible modification in structure ,is illustrated. The 7 instead of being formed each intwo pieces,

' "3 as shown in Fig. II, and as already deas are the bearing blocksscribed, are one-piece structures. These 'one-piece blocks afl'ord positive stop on the .right, and the fend-thrust bearings already described afi'ord positive stop on the left.

'Thus the positioning of the rolls is Wholly subject to control. It will be understood that Fig. III illustrates merely a permissiblemodification, and that if in a given installation this modification be not desired,

the bearings at both ends of the rolls will be the two-piece .bearings shown in Fig.II.

Incidentally, we find it desirable wholly to encase thebearings, as is best shown at the left-hand end,-Fig. I. This complete encasement affords improved facilities for lubrication, as will be perceived by anyone acquainted with this subject. Scale and water are excluded, and loss of lubricant is prevented.

We do not mean to limit ourselves to a mill /for rolling any particular material, or any particular shape, nor to roll, bodies of any particular configuration, nor do we limit ourselves to any particular arrangement of the means employed for achieving a roll having a tapered neck, of. a correspondingly tapered bearing, and means for resisting longitudinal movement of the roll in its bearings.

. 4. In a rolling mill the combination with a pair of rolls having tapered necks, of correspondingly tapered bearings, and athrustbearing for each roll adapted to resist longitudinal movement of the roll in its bearings. 5. In a rolling mill the combination with a roll having a tapered neck of a one-piece bearing block for saidroll neck at one end and a thrust-bearing for the roll at its ops1t e. end, the large end of said tapered arlng being. toward said thrust-bearing. In testimony whereof we have hereunto set purhands.

JAMES s. LOCHHEADI WARREN WORTHINGTON.

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