US3554118A

US3554118A - Relief and raising device arrangement in multinip calender

Info

Publication number: US3554118A
Application number: US704909A
Authority: US
Inventors: Paavo J Laine
Original assignee: Tampella Oy AB
Current assignee: Tampella Oy AB
Priority date: 1968-02-12
Filing date: 1968-02-12
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12

Abstract

A relief and raising device arrangement in a multinip calender or calender stack, in which upon a stationarily rotatable lower roll are mounted two or more superimposed rolls which are pivotably attached by arms to the calender body and in which each roll has its individual relief device attached to a common raising device. The relief devices are so attached to the raising device that the raising device will through the pneumatically regulated relief device constantly be in connection with the roll and that an adjustable free spacing for movement of the relief devices increases in the downward direction. The raising device is preferably a rod movable in vertical direction and attached to the lower or upper part of the calender body.

Description

United States Patent [72] Inventor Paavo J. Laine Tampere, Finland [21 1 Appl. No. 704,909 [22] Filed Feb. 12, 1968 [45] Patented Jan. 12, 1971 [73] Assignee 0y Tampella Ab Tampere, Finland a corporation of Finland [54] RELIEF AND RAISING DEVICE ARRANGEMENT $155,029 11/1964 Thomas Primary Examiner-Daniel Blum Attorney-Albert M. Parker [N MULTIN, CALENDER ABS'IIIACT: A relief and raising device arrangement in a Claims snrawing Figs multlmp calender or calender stack, in wh1ch upon a statlonanly rotatable lower roll are mounted two or more su- [LS- CI- e -imposed rons which are pivotabiy attached arms to the 100/170 calender body and in which each roll has its individual relief [51] Ill!- Cl. B301) device attached to a common raising device The relief devices are 5 attached 'to the raising device that the raising 163A, 170 device will through the pneumatically regulated relief device constantly be in connection with the roll and that an adjusta- [56] References C'ted ble free spacing for movement of the relief devices increases UNITED STATES PATENTS in the downward direction. The raising device is preferably a 2,850,952 9/1958 l-lombostel 100/ 163 rod movable in vertical direction and attached to the lower or 3,044,440 7/1962 Molsberry et a1 100/1 63UX upper part of the calender body.

1/1 lllIlIlllllV/II/ PATEN'TEDJAHIZIQYI 3.654.118 sutnanr a INVENTOR.

PAA v0 J L A/NE ATTORNEY.

l RELIEF AND RAISING DEVICE ARRANGEMENT MULTINIPCALENDER" BACKGROUND or THE INVENTION LField ofthelnvention: This invention relates. to a portion of the paper machine "known as calender or calender' stack and more particularly, to

an improvementin a multinip calender. f

2. Description of the Prior Art U.S. Pat. Nos. 2,850,952 and 2,985,100 disclose hydraulically or pneumaticallyoperated relief devices, which act on' the end of a lever mounted on the body and extending to the side of the calender .body opposite ofthe roll, andin which arrangement the raising device of' the rolls 'a'cts'on that end of said lever which extends toward theroll, th'at'is on th'e'opposite end withrespect-to the relief i'device. v This arrangement has the drawback that inlthe eventof paper accumulations squeezing into the nip between two tolls, the end of the lever facing. toward the" relief "device loses connection with the hydraulic or pneumatic, relief device, giving ,rise to shocks straining the'de-vice. Y I

THE SUMMARY OF Tm; INVENTION This invention relates to a reliefand raising device arrangement in multinip calender stacks of the type in whichupon a stationarily rotatable lowerv roll are mounted one upon the FlG. l shows a multinip calender stack provided with the re lief and lifting arrangement according toithe invcntiomin side elevation and in partial section; 2

F IG, 2 is adetail view of a single relief device insection; t

FIG. 3 is a side view of the apparatuss'imilar to theview of FIG. 1 'and with some parts cut away toshow internal stru ture; j FIG. 3a is a detail view of the liftin g arrangement of FIG. 3 in transverse section; I I

FIG. 4- is a sectional view of. the lower portion of the apparatus of FIG. 3 and taken at right angles-to the view of FIG. 3; m

FIG. 5 is a detail view, in section, of the relief device ofthe invention;

FIG. 6 is a view, in elevation, of a detail of the relief device;

F IG. 7 illustrates schematically an adjusting screw of the relief device of FIGS. 1 i

' DESCRlPTlGN or, THE PREFERRED EMBODIMENT In the drawing reference numeral indicates a calender body, Zisabearingfor the lower roll or lt'ing roll 3, reference transmission in housing 10 surrounds theipin 8 at its lower end and lifts orlowers the pin 8 by means of trapezoidal threads on the pin 8 engaging the internal threads of the fitting 9.

The drive means may obviously be any other mechanically or hydraulically operated suitable device.

I At spacedlocations along the lifting rod 7 there are provided adjustable mounted braces or'lugs l 1, below which the relief devices are mounted. Since the relief devices are arranged between the braces or lugs 11 and the ends of the lever arms 20 the expansion and contraction of the relief devices, braced by the lugsll, serve to raise and lower the ends of the lever arms 20. The lever arms 20'are longer than the lever arms 5 to which they are secured at pivot points 6, so the lever arms 5 convey a fraction of the movement of the relief devices to the rolls 4, lifting or lowering the rolls. Each of the braces or lugs 11 bears a downwardly extending cylindrical element extending into the adjacent relief device.

; The relief device comprises plates and 15 joined together by a bellows 13 of annular form. The lower plate 14 is identical in all relief devices, and'its upper surface, which remains inside the bellows, consists of an engaging surface 16, and its lower surface is provided with a central depression, into-which penetrates a stud 18 having at its lower end a T-branch 19 of circular section. This T-b'ranch is positioned in a recess 21 at the free end of one 20 of the arms of a lever. The relief devices are thus pivotallycoupled at 19 to the free ends of the lever arms 20. The upper plate 15 has in its lower surface remaining inside the bellows l3 amengaging portion 22, the height of pneumatic action of the bellow which moves the ends of lever mm 20, through the coupling 19, but'the bellows 13 is also effective to prevent the sudden jarring of the mechanism when a paper accumulation or paper cud passes between two rolls v4 of the calender. Because of the high speeds at which the rolls of modern calenders rotate, the import of a paper cud" passing between two rolls is veryforceful'andmight easily cause the failure of the raising mechanism if it were not for the shock absorbing effect of the bellows i 1 In the above described relief andiaisingdevice arrangement according to the invention the support force of the roll relief is not applied to the body but through the roll raising rod to thefoundation, which reduces the strains on the body Sudden shocks, as in the case of the passage of a paper cud between tow rolls 4, are thus conveyed throughthe raising rod 7 to the worm gear transmission at 10 to thebed or foundation. The arrangement according to the invention can how-.

numeralA'indica'tes generally the rolls-mountedupon the lower'roll in theyends of arms S-oflevers. The. levers are at points 6 pivotally mounted on the calender body 1, a driving means for a raising rod 7 being provided in the lower portion of said body. Beyond their pivot points6,- thelevers have arms 20 which arelongerthan the lever arms 5, thus providing a mechanical advantage to the relief devices tobe described in detailhereafterp The actuating mechanism for the raising-rod 7 includes a pin 8, which is 'pivotally secured to the lower end of the raising rod 7.A worm gear transmission mountedon the bed orfloor upon which the calender rests is shown enclosed in a housing 10. An internally threadedfltting 9 rotatable by the worm gear ever be utilized with the raising rod secured tothe upper portion of the body, in case the consequent additional strains on the body are deemed to be without'greater importance.

instead of using levers having pivotpoints 6 intermediate their ends as in the above description, it is-also possible to utilize a relief and raising device according to this invention with a different class of lever. Thus the rolls 4 could be secured to levers which have fixed fulcra" at one end and the raising and relief devices at their other ends, the rolls 4 being between the fulcra and the raising and relief devices.

The spacing between the

engaging surfaces

16 and 22 of the. relief device can be adjusted as required by raising or lowering the threaded member l2 in the lug .11. Since there is a mechanical advantage in the system the individual adjustment of the threaded cylindrical memberslZ is done in multiples ofthe spacing which is desired between adjacent rolls 4. Also, because of the cumulative. effect of the adjustments it.will be clear that the uppermost lug or brace 11 will be closer to the end of the adjacent lever arm 20'than the .next lower lug or pneumatic pressure inside the bellows can of course be individually controlled in each device.

In the arrangement of this invention the relief devices constitute a part of the raising device, because of which the rolls 4 through the

anns

20 and 5 are in continuous contact through the relief devices with the raising rod 7, and in the event of paper accumulations squeezing into the nip between two rolls this relief method and relief device arrangement provide more resilient shock absorption.

As has been stated above the invention is not restricted to the relief and raising device arrangement described above and shown in the drawings but can be varied within the scope of the following claims.

lclaim:

1. In a paper machine a multinip calender, comprising a calender body, a stack of calender rolls including a bottom roll and a plurality of superimposed rolls, separate and independent bearings rotatably carrying the ends of each of said superimposed rolls and separate arms pivotably attached to the calender body and independently carrying said bearings and independent pneumatic relief devices urging each of said bearings upwardly, said relief devices comprising expandable bellows elements, a common raising device coupled to said relief devices, said raising device being attached to the calender body for raising and lowering said bearings and being constantly in contact through said relief devices with said bearings, said relief devices having a free spacing increasing in the downward direction.

2. A multinip calender as claimed in claim 1, wherein each of said superimposed rolls is mounted at the end of one arm of a lever pivotably attached to said calender body, said raising device is provided at the opposite side of the body from said rolls and the said relief devices are pivotably in connection with the ends of opposite arms of said levers.

3. A multinip calender as claimed in claim 1, wherein sai superimposed rolls are mounted on levers pivotably attached to said calender body and said relief devices are pivotably secured to free end of said levers.

4. A multinip calender as claimed in claim I, wherein the free spacing for movement of said relief devices is adjustable.

Claims

3. A multinip calender as claimed in claim 1, wherein said superimposed rolls are mounted on levers pivotably attached to said calender body and said relief devices are pivotably secured to free end of said levers.

4. A multinip calender as claimed in claim 1, wherein the free spacing for movement of said relief devices is adjustable.