US2606080A

US2606080A - Roller grinding mill

Info

Publication number: US2606080A
Application number: US167140A
Authority: US
Inventors: Jack George
Original assignee: J M LEHMANN Co Inc
Current assignee: J M LEHMANN Co Inc; J M LEHMANN COMPANY Inc
Priority date: 1950-06-09
Filing date: 1950-06-09
Publication date: 1952-08-05
Anticipated expiration: 1969-08-05

Description

1952 G. JACK ROLLER GRINDING MILL 3 Sheets-Sheet 1 Filed June 9, 1950 INVENTOR Y MW" ATTORNEY-6' Aug. 5, 1952 G, JACK 2,606,080

ROLLER GRINDING MILL Filed June 9, 1950 3 Sheets-Sheet 2 L I INVENTOR, l g Mk. /9 B 5%, WW Mn+e0m ATTORNEYS Aug, 5, 1952 k G, JACK 2,606,080

ROLLER GRINDING MILL Filed Jun 9, 1950 5 Sheets-Sheet s r/z ATTORNEYS Patented Aug. 5, 1952 ATENT OFFICE ROLLER. GRINDING MILL George Jack, Rochelle Park, N. .L, assignor to J. M. Lehmann Company, Inc, Lyndhurst, N. .L, a corporation of New York Application June 9, 1950, Serial No. 167 ,140

This invention relates vto improvements in grinding mills of the type having a plurality of grinding rollers disposed in train with their axes in a single plane and parallel to each other with a feed and grinding roller offset from the plane of the other rolls, usually at one end thereof, and wherein the relative positions of the rollers are adjustable to vary the distance between them and also to change their operating pressures in order to adapt the mill for the treatment of different materials. Generally in a mill of this type, the roller at one end of the train is journaled in fixed bearings, while the bearings of all the other rollers in the train as Well as the bearings of the offset feed and grinding roller are adjustable in relation thereto. Thus in a mill of this type having, for example, a train of four rollers in addition to the offset feed roller, as many as eight separate adjustments (two for the bearings of each roller) have sometimes been required to adapt the mill for treating a given material.

One of the objects of the present invention is to substantially reduce the number of bearingadjustments in such a mill, by eliminating the necessity for independently adjusting the positions of the rollers intermediate the top and bottom rollers of the train. Since the separate adjustment of these intermediate rollers requires the exercise of skill and judgment on the part of experienced operators, the elimination of the necessity for this saves both time and expense in mill operation.

Another object of the invention is to provide means whereby, once all the rollers have been adjusted to their desired operating positions and the mill has completed its run on one batch of material, the rollers of the train may be instantly separated to avoid injury to the surfaces of the rollers, so that the mill may be cleaned, and in order that the rollers may be readily returned to their already adjusted operating positions. The utility of the invention in the foregoing and other respects will appear more fully from the detailed description thereof which follows.

In the accompanying drawings, Figs. 1 and 2 are respectively a top plan and a side elevation of a -rol1er mill of the type referred to having four grinding rolls or rollers disposed in a ver-- tical train and a feed and grinding roller offset at the bottom of the train; Fig. 3 a larger scale section taken on a plane indicated by the line 33 of Fig. 4; and Fig. 4, a front elevation thereof, partly in section and with some of the parts omitted for better illustration.

The mill shown in the drawings may be driven 6 Claims. (Cl. 308-60) 2 by a motor 10 the shaft of which is belted to a pulley H fast on one of the journals of the top roller 12 of the vertical train of four rollers there shown. The bearings for each end of the roller l2, denoted generally by the numeral [3, are slidably mounted for vertical adjustment in the respective pairs of frame members l4, l4, one pair at each end of the mill. Of the other three rollers in the train, the bearings [5 of the bottom roller l6 are permanently fixed, as shown, to the end frame members I4, I l while the bearings of the intermediate rollers l1 and I8 are slidably mounted for vertical adjustment in these end frame members, the same as in the case of the bearings of the top roller l2. The bearings of the lowermost roller l9 which is ofiset from the train and which, together with the bottom roller 16 of the train, constitute the initial feed and grinding rollers, are mounted in the frame, as shown, for horizontal adjustment toward and from the fixed bearings of the roller it.

The rollers I1, l8, l6 and I9 are driven from roller I2, being operatively connected with one of the journals of that roller in such manner that roller I! will rotate at slower speed than that of roller l2, the roller is at slower speed than that of roller l1, the roller l6 at slower speed than that of roller 18, and the roller [9 at slower speed than that of roller It, so that when'the mill is operated with the rollers in their operating positions each will have a rubbing contact with the adjacent roller or rollers to assist-in reducing the material under treatment. This relative difference in the speed of rotation of adjacent rollers may be brought about by a train of gears, such as shown in Fig. 4, whereof the gears 20, 2|, 22 and 23 are fast on the journals of the respective rollers l2, l1, l8 and I6 and mesh respectively with

larger gears

24, 25 and 26 fast on the journals of the respective rollers l1, l8 and I6, and with a gear, which is not shown, on the journal of the roller l9.

Each bearing [3 of the roller i2 is linked to the bearing next below of the intermediate roller l! by a pin 28, and each bearing of roller I1 is similarly linked to the corresponding bearing ;of the other intermediate roller [8 by a pin 29-. For a purpose presently to be explained each of these

pins

28, 29 is closely fitted to the lower of the two bearings which it connects but has a slight clearance, denoted in Fig. 4 by the numerals 28' and 29', with the upper of said two bearings.

For adjusting the bearings of the top roller 12 up or down in the frame members l4, ['4' in order toadjust the position of thatroller-relative to 3 the fixed bottom roller Hi as well as to the other rollers in the train, means controlled by two hand-wheels 30, are provided, one handwheel for each of the bearings I3. On each said hand-wheel is a worm 3| which meshes with a worm-nut 32 threaded to an eyebolt 33 firmly secured to the adjacent bearing l3 of the top roller. The .shank of'this boltis'free tomove up and down in the'hollow thrust-head of a ram indicated at 35 and secured to the casing 36 which supports said adjustin means and is slidable on the mill frame. The nut' 32*bears, at one side, against the thrust-head 34 and, at the other side, against the casing 36,;so' that when the hand-

wheels

30, 3| are turned in one direction the bearings of the top roller will be moved downwardly to cause that roller'tocontactzand press upon the intermediate roller l'! next below; and when the hand-wheels are turned in'the opposite direction the pressure between these two *rollers and between the other rollers of -the columnwillbe"relieved andthe-rollers separated from each other.

Since the top roller adjusting mechanism just describedis the subject of a pending patent application filed September 27,1949, Serial Number 1 l8,05'l ',now PatentNo. 2,592,048, dated April 8,1952, no claim therefor is made here apart from its use in conjunction with the present improvements.

Assum'ing now that therelative positions of the' fourrollers' in the vertical column are such "that=each-saidroller is in working relation with respect to its adjacent rolleror rollers,-and that the han'd-

wheels

30,3! are turned in-a direction nekt interrnediate roller I! by a predetermined amount, say of aninch, before the adjusting "movement'of the top roller affects said roller H;

"but that by continuing the upward adjusting "movement of the top :roller the intermediate roller 11 -will be caused to separate from the next intermediate roller I8 by' a predetermined -.amount, sayalso 1% of aninch; then, by a'still :further upward'adjusting movement of the top -roller, the intermediate roller. I8.will.be caused to separate'from theifixed-bottomroller It by a predetermined amountsay again {got an inch. :Hence, when the'top roller has been adjusted :awayffromthe fixedbottomroller I6 bya' total of fig lnch; there .will then be a clearance of 1% of an inch between each'of the rollers l'2,' l1, l8 andlfi. Conversely, t-whe'n, with-these rollers in "their open or separated positions, the handiwhe'elsIM, 3 I are tumediin a. direction to-read *Justthe 'mill to its operating condition again awith all' these rollers in working'relation to each other, the uppermost three rollers will move downward together as a unit until the inter- Jnediate roller [8 assumes its working relation .toithev fixed bottom roller 16 and stops; then the twouppermost rollers will move as'a. unit until the intermediate roller 1'! assumesworking relatlon 'tothe intermediate roller 18 and stops; and

flnally the top roller l2 will move-alone until it assumes working relation to the intermediate roller l1. Further adjustment of the top roller toward the fixed bottom roller [6 will now cause pressure to be applied between the working surfaces of these four rollers, the degree of which is registered by two pressure gauges 31 (Fig. 2) communicating respectively with the cylinders of the rams 35. When these gauges register the degree of pressure desired between said rollers for the treatment of any given material, the mill, so

far as the rollers l2, l1, l8 and i6 are concerned.

is ready for operation upon that material.

It will be understood by those skilled in the art that the adjustment of the rolls toward "workingyrelation to each other is carried out when-the surface of at least one of the rolls is covered with material to be treated, thereby avoiding injury to the roll surface due to the speed"differential between surfaces which would otherwise be in contact.

Afterthe mill has completed its run onany batch o'f material and itiis desired to make a new run of .the millon material of a different nature, the mill will ordinarily need to be cleaned to remove all traces of the previously treated material. For this purpose it is desirable that the rollers be separated sufliciently to make all the parts accessible for thorough cleaning; and where the new run is to be made with the same roller adjustment as before, it is also desirable that means be provided forinstantly separating the rollers l2, l1, l8 and I6, that is, without re- .sort..to the. adjusting meansalready described,

.and then instantly returning them again to their previously adjusted positions. Accordingly, each bearing l3 of the top rollerlz isprovided .with a rotatablemember '38 carrying a "cam-39 which is embraced by the eye of the bolt '33 aforesaid, so that by apartial rotation of. the members 38, each of the bearings I3 of the toprrollermay beinstantly raised, together with the 'bearingsof the intermediaterollers [land I8 through their linkage connections with the bearings of the top roller. .This will cause'all of the rollers in the'train'to be separated from each-other and thusprovide a sufficient-clear- 'ance between them for cleaning. The rotation of .the 'members 38 mayibe effectedby a bell crank lever dflfulcrumed at 4|. and: connected by links 42. to crank arms 43 respectively provided on the rotatable membersi38. As shown in. Fig. 2, the swinging of this lever through an arc of about degrees from itsfull line position to its broken-line'position in that figure will cause the instant separation of the. rollers; and 'the swinging'of this lever back to its full line position Willinstantly return the rollers again to their operating positions without necessitating any readjusting of their relative positions by the hand-

wheels

30, 3|.

Theproper adjustment of the offset feeding and grinding roller l9 relative to the bottom roller 16 .of the vertical column may be effected by adjusting means substantially the same as the adjusting means described aforesaid for the bearings of the top roller l2, and which, as aforesaid, is the subject of the pending patent application filed September 27, 1949, Serial Number 118,057 above mentioned. This adjusting means whichis applied to each of the bearings '01 the roller l9 may be similarly operated by two hand-wheels 45, 45' and will be understood without further explanation.

Thus a 5-roller mill of the type shown in the "drawings and which, as-heretoi'ore constructed,

5 sometimes required eight separate roller adjustments to accurately position the rollers for operation, may, in accordance with the present improvements, have all its rollers positioned for practical operation by only four rolleradjustments which are accomplished through the four hand-wheels aforesaid in the manner above described. In former 5-roller mills built with eight hand-wheels, one pair for each adjustable roller, the manipulation of one pair of hand-wheels to adjust the position of one of the intermediate rollers of the train will obviously affect the setting of the adjacent roller or rollers; and it is because of this that adjustment of a 5-roller mill as so constructed is extremely difficult for an inexperienced operator; and great care and good judgment have always been necessary to obtain optimum'results from theopera-tion of such mills. The present improvements make it possible to adjust a mill for its best performance in far less time and by operators who have not had long experience and do not possess the best of judgment.

In short, the precision of adjustment required for 5-roller mill operation is, so to speak, built into the mill by the incorporation of the present improvements, thus leaving only a relatively simple primary adjustment for the operator.

It may be observed, however, that the use of the improvements thus far described herein would not result in providing substantially equal pressures between the rollers IE, IT, l8 and it when the mill has been adjusted to its operating condition by the adjustment aforesaid of the top roller. The reason for this is that the pressur between the intermediate rollers H and 13 would normally exceed the pressure between the top roller and the roller I? by the weight of the roller ii, and that the pressure between the intermediate roller iii and the bottom roller 18 would normally exceed that between the intermediate rollers l! and it by the weight of the roller It. In the treatment of most materials this pressure differential would not be detrimental to mill operation but in the case of a few materials it might be. Accordingly, the present improvements include means whereby, if desired, the pressures between the different rollers in the vertical column may be equalized. These means consist in the provision of spring supports for balancing or overcoming the weight of the intermediate rollrs IT and I8 respectively. As embodied in the mill shown in the drawings, such spring supports are provided by levers 4B and 4'! fulcrumed to the mill frame at Q6 and M respectively; the upper arms of these levers are substantially horizontal and bear directly upon the

pins

28 and 29 respectively, while their lower arms which are substantially vertical are urged inwardly by compression springs it and 49. These springs are adjustable so as to impart to the pins 25, 29 precisely the amount of upward pressure required to balance the weight of the respective intermediate rollers H and 53. The adjustment of these springs will ordinarily be made at the factory; and once adjusted, they require no further adjustment or attention by an operator.

The provision of these spring supports has the further advantage that when the top roller is raised or adjusted to release the pressure, the springs will tend to lift the intermediate rollers i1 and i8 and cause separation between the rollers l7, l8 and It. In treating some materials of extremely low viscosity and tackiness, the roller pressure should be accurately proportioned or set exactly the same between each pair of rollers.

B I s of his nature, it will be understood that thesprings 48 and 49 may be so adjusted as to make the intermediate rollers l6 and I?! practically weightless or just floating in operative position.

Bearing in mind that the several rollers are geared to bedriven at different speeds usually at increasing relative speeds from the feed roll through the train to the top roller, it will be apparent to those skilled in this art that injury to the roll surfaces may very well take place if they are run dry, that is to say, without any treated material passing through the mill. If therefore the rolls are not quickly separable by throwing'the lever 40 when the supplyof material passing through the mill 'is exhausted, injury to the roll surfaces may result and it is for this reason that the spring supports are valuable in conjunction with the former taking up any lost motion in the latter and making it easierto'lift the upper and two intermediate rollers.

In operating the mill shown in the drawings, the material to be treated is delivered into a hopper 5% (Fig. 2) which feeds the material between the rollers I6 and I9. As these rollers revolve, the material which passes between them adheres to the surface thereof and continually passes successively from the roller it to each of the rollers above in the vertical column until it reaches the top roller l2 from the surface of which it is scraped by a knife (not shown) .on the inner edge of a receivin pan or discharge chute 5i (Figsl and 2) into which the scrapedoff material drops. This feature of the mill c onstitutes no part of the present invention nor does the water cooling system for the rollers, a part of whichis indicated by a pipe 52.

I claim as my invention: 1

1. A roller grinding mill comprising a plurality of rollers disposed one above another in a substantially vertical train, a hearing at each end of each roller, frame members at each end of the mill in which all said bearings but those of the bottom roller of the train are slidable, means to adjust the position of the top roller of the train relative to the bottom roller of the train, and means to link the slidable bearings together comprising pins each of which connects an adjacent pair of these bearings and is closely fitted to one of said pair but has a clearance with the other of said pair.

2. A roller grinding mill comprising a plurality of rollers disposed one above another in a substantially vertical train, a hearing at each end of each roller, frame members at each end of the mill in which all said bearings but those of the bottom roller of the train are slidable, means to adjust the position of the top roller of the train relative to the bottom roller of the train, and means to link the slidable bearings together comprising pins each of which connects an adjacent pair of these bearings and is closely fitted to the lower bearing of said pair but has a clearance with the upper bearing of said pair.

3. A roller grinding mill comprising a plurality of rollers disposed one above another in a substantially vertical train, a bearing at each end of each roller, frame members at each end of the mill in which all said bearings but those of the bottom roller of the train are slidable, means to adjust the position of the top roller of the train relative to the bottom roller of the train, and means to link together respectively the slidable hearings in each end frame member the 76 said last named means having spring supports 7 toibalance respectiVeIy the weights of eachroller of the train intermediate the top and bottom rollers of .thetrain.

4. A' roller grinding mill comprising a plurality of rollers disposed one above another in a substantially vertical train, a hearing at each end of each roller; frame members-at each end of the mill 'in' which all said bearings but those of the bottom roller of the train are slidable, means to -adjust the position of the top roller of the train relative to. the bottom roller of the train, and means to link together. respectively the slidable bearings in each end frame member the said last named means-having spring supports to balance-respectively the weights of each roller of the train intermediate the top and bottom rollers of the-train, each said spring support comprising a lever, one arm of which is operatively connected to one-of the bearings and a spring applied to the other arm of the lever to impart an upward pressure of the first named arm.

5. A roller grinding mill comprising a plurality of rollers disposed one above another in a substantially vertical train; a hearing at each end of each roller, frame members at each end of the mill in which all said bearings but those of the bottom roller of the train are slidable; means to adjust the position of the top roller of the train relative to the'bottom roller of the train, means to link together respectively the slidable bearings in each end frame member, and spring supports to balance respectively the weights of each rollerof the train intermediate the top and bottom rollers ofthe train, and in which the means to link the slidable bearings together comprise pins each of which connects one of the slidable hearings to the slidable bearing next below it, and each said spring support comprising a lever one arm of which contacts one of the connecting pins, and a spring applied to the other 8 arm of the lever to impart an upward pressure to. that said pin and through said pin to the bearing below it.

6. A roller grinding mill comprising a plurality of rollers disposed one above another in a. substantially vertical train, a hearing at each end of each roller, frame members at each end of the mill in which all said bearings but those of the bottom roller of the train are slidable, means to adjust the position of the top roller of the train relative to the bottom roller of the train, means to link together respectively the slidable bearings in each end frame member, and spring supports to balance respectively the weights of each roller of the train intermediate the top and bottom rollers of the train, and in which the means to link the slidable bearings together comprise pins each of which connects one of the slidable bearings to the slidable bearing next below it, and each pin being closely fitted to the said bearing next below but having a clearance with the other said bearing, and each said spring support comprising a lever one arm of which contacts one of said connecting pins. and a spring applied to the other arm of the lever to impart an upward pressure to said pin and through said pin to the-lower of the two bearings which it connects.

GEORGE JACK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS