US2300994A - Calender for paper - Google Patents

Description

Nov. 3, 1942. w. F. 'rl-HELE ETAL CALENDER FOR PAPER Original Filed March 12. 1956 3 Sheets-Sheet l www@ N0v 3, 1942. w. F. 'rl-HELE: ETAL CALENDER FOR PAPER Original Filed March 12. 1936 5 Sheets-Sheet 2 jz @il fo f5 N0v 3, 1942 w. F. THU-:LE ETAL 2,300,994

f CALENDER FOR PAPER Original` Filed March 12, 1936 3 Sheets-Sheet 3 n Patented Nov. 3, 1942 asoman cnLENnEn ron PAPER William F. Thiele and Bert F. Barmer, Wisoonsin Rapids,` Wis., assignors to Consolidated Water Power & Paper Company, Wisconsin Rapids, Wis., a corporation of Wisconsin t Continuation of application' serial no. canse,

March 1 1938, Serial No. 223,852

(Cl. SI2-73) 4 Claims.

This is a continuation of our pending application, Serial No. 68,486, filed March 12, 1936. f

Our present invention has reference `to the paper making art and more particularly to that phase of paper making 'known as calendering.

Up to the present time it has generally been considered impractical to operate super-calendering apparatus adjacent the "dry end" of a paper making machine, for directly receiving a web of paper from the machine for producing supercalendered paper, because of the great likelihood of injuring the highly finished surfaces of the super-calender rolls.

Super-calendering `devices generally include a stack of superimposed rolls, some of which are provided with hard metallic surfaces such as chilled iron, steel, etc., while other rolls are provided with more or less resilient surfaces composed of material such a paper filling, cotton or combinations of cotton and paper and also cotton and asbestos, paper and asbestos, or paper, cotton andasbestos. A stack of super-calender rolls are i usually arranged with a resilient surface roll y positioned for contactual engagement with a highly finished metallic surfaced roll. This relationship tends to protect and preserve the highly finished metallic surfaced rolls, while producing desired characteristics in the finished calendered surface of the paper. The possibility of injuring the finished surfaces of these rolls, and particularly the resilient surfaced rolls,` is greatest during the initial threading of the web of paper into the super-calendering device. It is well known that during this operation wads of paper are frequently passed through `the bight of cooperating rolls of the stack, and such wads of paper frequently accumulate and produce depressions or indentations in these highly finished surfaces of the resilient surfaced rolls. If such injury becomes sufficiently serious the calendered finish of the paper is greatly impaired and is rendered unsuited for use. When this condition occurs it is necessary to remove the roll from the stack and reflnish its external surface. Th'e operation of refinishing the surface of either the metallic rolls or the resilient surfaced rolls is very expensive and adds materially tothe cost of producin calendered paper. i

The `present invention is directed to a novel I arrangement and provision of mea'ns directed to eliminate the foregoing difficulties by separating all of the rolls in the calender stack duringthe initial threading operation of the web of paper,

and driving each roll while said `rolls are in sepa- 2, 1936. This application August 9,

threading of the web of paper in'a. tortuous path through the series of rolls, and practically eliminates entirely the possibility of damaging the surface ofthe rolls by paper wadding being forced into the resilient surfaces of the rolls during the initial threading operation, `as heretofore has been the case.

Another feature of our invention consists in" `for producing certain desired characteristics in thenished calendered surface of the paper.

Other features and advantages of our invention will be manifest from the drawings taken in connection with the following description.

In the drawings, i

Fig. 1 is a diagrammatic illustration of several mechanisms which may be employed at the dry end of a paper making machine, including a calendering device embodying our invention.

Fig. 2 is a side elevation of a super-calendering device constructed inaccording with our present invention.

Fig. 3 is a. fragmentary sectional view through the far end of the super-calendering device as viewed in Fig. 2, showing the friction driving arrangement of the calender rolls.

Fig. 4 is a diagrammatic illustration in end view of the friction driving 'arrangement for `the calender rolls.

Although the present invention may be applied to a conventional calendering device associated with a paper making machine, resulting in obtaining considerable advantage over present constructions now in use, such as facilitating the threading of a web of paper through the device' and avoidance of possible injury to the finished surfaces of the calender rolls, it is believed that our device is particularly suitable and may be more advantageously employed in connection with a super-calendering device as illustrated in rated relation. This arrangement facilitates the The web of paper I2 then travels through a storage reel indicated at |5. As is well known in the art the regular calendering device is composed of a stack of superimposed rolls all of which are provided with relatively hard metallic surfaces such as chilled iron, steel, etc., while in a super-calendering device the stack of rolls which are also arranged in superimposed relation consist of some rolls having hard metallic surfaces and some having resilient or soft surfaces. Super-calendering devices at no time have two rolls with hard metallic surfaces arranged in cooperating relation for engaging the web of paper therebetween, but on the contrary a soft or resilient surfaced roll is generally positioned for cooperative relation with a hard metallic surfaced roll for obtaining certain characteristics in the finished calendered paper, while also serving to protect the highly finished surface of the metallic roll.

In the super-calendering device illustrated in the drawings, reference character 29 designates base members for two upwardly extending side frames 2|, to the upper ends of which are pivotally mounted as indicated at 22 longitudinally extending beams 23, the forward ends of which together with the side frames 2| serve to position and at times entirely support a plurality of calendering rolls arranged in superimposed relation. For convenience we have shown a super-calendering device composed of six rolls indicated as 26, 21, 28, 29, 3| and 3|, and the rolls designated as 26, 28, and 3| may be understood to be provided with highly nished hardened metallic surfaces, while the other rolls, 21, 29 and 30 have resilient, highly nished surfaces of material such as paper, cotton, etc. It has been found, however, that very satisfactory results may also be attained when using a greater or lesser number of calender rolls. The bottom roll 26 is provided at opposite ends with stub shafts 26a, journalled in bearing 26h secured to the bases 20. One of the stub shafts 26a as indicated in Fig. 3 ofthe drawings is extended for connection to a main source of power. The upper roll 3| is provided with stub shafts 3|a at its opposite ends, Journalled in bearings 3|b which are secured to the underside of the pivot beams 23. 'Ihe other rolls 21, 26, 29 and 36 are each provided with stub shafts 21a, 28a, 29a and 30a at their opposite ends and are journalled in similar'bearings designated as 35 which are formed as integral parts of lever arm 36, the ends of which are of yoke formation and are pivotally connected by pivot pins 31 to the respective side frames 2|. Each of the lever arms 36 is provided with forward extensions 38 beyond said4 bearings 35, the outer ends of said extensions being connected together by the rods 40, and slotted links 4|. Said links 4| are connected to the ends of the respective arms 38, by pins 42, and the upper end of each of the uppermost rods 49 is provided with an eye nut 43, pivotally connected at 44 to the pivoted beams 23. Each of the connecting rods 4U is provided with a turnbuckle 49a, for minute adjustment of the eective length of the connecting rods.

The slotted openings in the connecting links 4| vary, increasing from top to bottom for insuring proper separation and spaced apart relation of the respective calender rolls when the beams 23 are swung about the pivots 22 by means hereinafter described, for the purpose of initially threading a web of paper through the stack of calender rolls. Associated with the upper five calender rolls are conventional doc-v, tors indicated at 48 which may be equipped with conventional compressed air nozzles indicated at 49. These doctors, as is well known in the art, function to keep the rolls free from specks and scabs of paper, lint, dirt, etc., and prevent the paper from running around the roll when it is fed into the stack during the threading operation. 'I'he bottom roll is provided with a conventional doctor indicated at 50 which is arranged in slightly different relation to the roll as compared with the other doctor 48, but functions in the same manner.

To apply pressure to the nip or bight of the rolls in excess of that furnished by the weight of the rolls themselves, fluid pressure is employed to react on the beams 23 and force said rolls toward each other. For this purpose there is provided two cylinders 55 containing pistons 55 connected by rods 51 to the forward ends of the beams 23 with coil springs 58 interposed between the beams and the ends of said rods 51. Fluid is admitted to the cylinder 55 under high pressure such as a range of 1500 to 3000 pounds.` per square inch, and for normal operation the :duid is admitted to the cylinder above the piston 56 causing the piston to travel downwardly to the end of the cylinder. 'I'he pressure is thus transmitted through the beams 23 to the entire stack of rolls. The pressure applied to the rolls may be varied some by means of turnbuckles 51a connected in the upright rods 51. The coil springs 53 serve the additional function of pro-- viding a yielding connection for imparting forcel to the beams 23, and it will be apparent that f should paper of unusual thickness pass through the bight of any pair of cooperating super-cal-l ender rolls, when once set for thinner paper, the rolls will be permitted to separate by reason of, the coil springs 59. Si.

When it is desired to separate the rolls to facilitate threading of a web of paper therethrough in I the tortuous path, the iiuid pressure above pistons 56 is released and fluid pressure is then admitted to cylinders 60 located on the rear endof the frames 2|, forcing the pistons 6| in a downward direction. These pistons are connected by rods 62, at pivots 63, to the rearward extension 23a of the pivoted beams 23, swinging said beams in clockwise direction with respect to the position seen in Fig. 2 of the drawings, and through the medium of the connecting rods 40 and links 4|, the calender rolls are caused to be raised one by one in spaced apart relation to each other, about the pivot connections 31, of the lever bearings 36. As the successive connecting links 4| are moved upwardly, there is a limited range of lost motion, until the lower end of the slots engage the under side of the pin 42 at which time it picks up and raises the next calender roll carried by the adjacent supporting lever arms 38. The rolls may be returned to normal operating position again by merely releasing the fluid pressure in cylinders 60 above the pistons 6|, and fluid under pressure may again be introduced above the pistons 56 in the cylinders 55. Any suitable valve arrangement desired may be employed for controlling the operation of these pistons in their respective cylinders.

Generally calender devices are operated by driving the bottom calender roll only, the remaining rolls being operated through frictionv with the rolls on which they rest. To carry out our invention, however, each of the calender rolls is driven by means other than friction due solely to the weight of the rolls themselves. t Rigidly mounted on the stub shafts of the respective calender rolls at one side of the device, as indicated in Fig. 3 of the drawings, are grooved pulleys indicated as 26e, 21e, 28e, 29e, 30e, and lc over which are trained in proper driving relation fiexi ible driving belts 65, as seen in Figs. 3 and 4, which may be V-type belts or Tex-ropes, and these flexible belts are .trained over an idler sheave 68 mounted on a stub shaft 69 journalled 3 in a bearing 10 secured on the upper edge of the adjacent pivoted beam 23. Said driving belts are also trained around an idler sheave I2 journalled on a laterally extending arm 13 which is mounted on the stub shaft lla and is provided with an adjustable counterweight 'I5 at its outer end. ,This counterweight together with lever arm 13 tends to automatically take up any slack in the friction drive belt and maintains a uniform driving tenson in the belt at all times. In this arrangement it will be observed that the upper five calender rolls are driven from the bottom roll 26 by means of the friction belt 65. However, it will be manifest that these rolls could, if desired, each be driven through separate power connections, or in other arrangements. The arrangement shown, however, is particularly suitable since it readily permits of automatic adjustment to enable the calender rolls to be driven yeven when the rolls are separated, to assist in threading a web of paper through the calender.

By manual adjustment of the friction belt tightener while the calender rolls are operated under pressure, it may be possible to obtain some desired variation in the calendered finish of the paper.

When paper is super-calendered as a separate operation from a paper making machine, it is `super-calendering they are necessary to correct defects in the making of paper and when the y super-calender is a, part of the paper making machine, these defects become immediately apparent and may be readily corrected. However, should it be found necessary to employ fly rolls they may be added, and the web of paper may be threaded through the stack by means of Sheenan carrier ropes in lieu of the use of air through the doctors as used in the conventional manner.

In actually employing our invention in a commercial Way we have found that very excellent results are obtained by merely separating the calender rolls approximately 1% of an inch. It

has been found that this amount of separation is adequate to prevent waddingof paper in a manner that would impair the finished resilient surfaced rolls during the threading of the web of paper in the calendering device. We have found by actual test runs of commercial quantities of paper in employing a super-calender constructed in accordance with our present invention that we were able to effect a saving in the cost of production of paper from at least three dollars to four dollars per ton. Not only will this substantial economy result from the use of our invention, but there is a considerable saving ln time in that delayed by necessity of renlshing the resilient surfaced rolls.

As above indicated, although we have illustrated and described our invention in its preferred embodiment in connection with a supercalendenng device, we believe that substantial benet .and advantage will result in the embodiment of our invention in connection with conventional calendering devices. It is also manifest that various other types ol' drives for thel calender rolls and `other types of separating mechanisms therefor may be employed without departing from the spirit and scope of our invention. We do not, therefore, wish to be understood as limiting our invention to the particular embodiment herein illustrated and described, or its arrangement and asociation with a paper making machine, except as limited in the appended claims.

We claim as our invention:

1. A paper calender which comprises in combination a frame, a shaft carried uponr said frame, a roll mounted upon said shaft, said roll having a stationary axis, a plurality of shafts positioned in substantially vertical alignment above said flrst mentioned shaft, rolls carried upon said shafts, means for movably supporting each of said plurality of shafts upon said frame, adjustable means connecting adjacent supporting means together, a lever pivotally mounted upon said frame, means for rocking said lever, adjustable means connecting said lever to said movable supporting means to move said plurality of rolls away from each other and away from said first mentioned roll when said lever is rocked, a ilexible drive element, and means carried upon each of said shafts engaging the exible drive element t drive said rolls when in separated relations p.

2. A paper calender which comprises in combination a frame, a shaft carried upon said frame, a roll mounted upon said shaft, said roll having a stationary axis, a plurality of shafts positioned in substantially vertical alignment above said first mentioned shaft, rolls carried upon said shafts, means for movably supporting said plurality of shafts upon said frame, adjustable links connecting adjacent movable means together, a lever pivotally mounted upon said frame, fluid actuated means for rocking said lever, an adjustable link connecting said lever to said movable supporting means to move said plurality of rolls away from each other and away from said first mentioned roll when said lever is rocked, a ilexible drive element, and means carried upon each of said shafts engaging the flexible drive element to drive said rolls when in separated relationship,

3. A paper calender which comprises in combination a frame, a shaft carried upon said frame, a roll mounted upon said shaft, said roll having a stationary axis, a plurality of shafts positioned in substantially vertical alignment above said first mentioned shaft, rolls carried upon said shafts, means for movably supporting said plurality of shafts upon said frame, links having adjustable effective lengths connecting adjacent supporting means together, a member movably mounted upon said frame, means for moving said member, a link having adjustable effective length connecting said member to said movable supporting means to move said plurality of rolls away from each other and away from said rst mentioned roll when said member is moved, a

the super-calendering operation of paper is not iiexible drive element, and means carried upon each of said shafts engaging the iiexible drive element to drive said rolls when in separated relationship.

4. A paper calender which comprises in combination a frame, a shaft carried upon said frame, a roll mounted upon said shaft, said roll having a stationary axis, a plurality of shafts positioned in substantially vertical alignment above said first mentioned shaft, rolls carried upon said shafts, a plurality of pivoted levers for movably v10 supporting said plurality of shafts npon said frame, adjustable means connecting adjacent levers together to space said rolls predetermined distances from each other, a member movably mounted upon said frame. means for moving said member, means connecting said member to said pivoted levers to move said plurality of rolls away t from each other and away from said rst mentioned roll when said member is moved, a flexible drive element, and means carried upon each of said shafts engaging the flexible drive element to drive said rolls when in separated relationship, and separate means connected to said member to move the same in the opposite direction to move said rolls together.

WILLIAM F. I'I-IIELE. BERT F. RAPRAGER.

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