US2804275A

US2804275A - Flexible web tension control mechanism

Info

Publication number: US2804275A
Application number: US405394A
Authority: US
Inventors: Saco Felix; Rockstrom Leonard
Original assignee: Cameron Machine Co
Current assignee: Cameron Machine Co
Priority date: 1954-01-21
Filing date: 1954-01-21
Publication date: 1957-08-27
Anticipated expiration: 1974-08-27

Description

Aug. 27, 1957 F. sAco ETAL FLEXIBLE WEB TENSION CONTROL MECHANISM 14 Sheets-Sheet 1 Filed Jan. 21, 1954 QINVENTORSI Fe/lx Saco and L eonavo'l -Eoc/ ,s7"ram Aug. 27, 1957 F. sAco ETAL I FLEXIBLE was TENSION CONTROL MECHANISM l4 Sheets-Sheet 2 Filed Jan. 21., 1954 m m m V m Fe/1Z1: ,Saeo anal Leonard Roe/rsl'rom ATTORNEY Aug. 27,

sAco ETAL FLEXIBLE WEB TENSION CONTROL MECHANISM Filed Jan. 21, 1954 14 sheets sheet 3 If I ll llllllllllllhlllh'lll'll IIIIL mm. om mm INVENTORS Aug.'27, 1957 F. sAco ETAL 2,304,275

FLEXIBLE WEB TENSION CONTROL MECHANISM Fil'ed Jan. 21, 1954 14 Sheets-Sheet 4 Felix Sucq 02.1101 9 Leona-r-cZ Rq cks-Prqm ATTORNEY v IIQVENTORS Aug. 27, 1957 F. SACO ETAL 2,804,275

FLEXIBLE WEB TENSION CONTROL MECHANISM Filed Jan. 21. 1954 14 Sheets-Sheet 5 F/Ci', Z

INVENTORS Felix Saco and Leonard Rocks/ram v ATTORNEY Aug. 27, 1957 F. sAco ETAL FLEXIBLE WEB TENSION CONTROL MECHANISM 14 Sheets-Sheei 7 Filed Jan. 21, 1954 INVENTORS Y N m m .w T A J-m k f q .R Md 0 5 we .3 Wm

,/Aug, 27, 1957 F. sAc0 ETAL 2,804,275

FLEXIBLE WEB TENSION CONTROL MECHANISM Filed Jan. 21, 1954 l4 Sheets-Sheet 8 gnu MM INVENTORS' j -Fe//z: ,saco and W Leena-rd Rocksfl-rom ATTORNEY Aug. 27, 1957 F. sAco ETAL 2,804,275

FLEXIBLE WEB TENSION CONTROL MECHANISM Filed Jan. 21, 1954 14 Shets-Sheet 9 z. INVENTORS Felix Saco and L eon a'rcl fioc/rsham ATTORNEY Aug. 27, 1957 F. SACO ETAL 2,804,275

FLEXIBLE WEB TENSION CONTROL MECHANISM Filed .Jan. 21, 1954 14 Sheets-Sheet 10 IN VENTORS F'el/x Scgco cuvcZ Leona-rel Flock .s-l-v-om ATTORNEY 14 Sheets-Sheet ll F. SACO ETAL FLEXIBLE WEB TENSION CONTROL MECHANISM Aug. 27, 1957 Filed Jan. 21. 1954 INVENTORS Saco ancZ rel Rocks-from L 1 \R ,Vi \m:

3 Inf/74 ATTORNEY Aug. 27, 1957 F. sAco ETAL FLEXIBLE WEB TENSION CONTROL MECHANISM 14 Sheets-Sheet 13 Filed Jan. 21. 1954 H .r|...||| 6 m n w llililvlillililli ll. 15L

FILTLIRIIO IDLER ROI-[- N VENTORS m dr a s k oc 2: .xd Qua n M o e =4 a a K n.

ATTORNE 14 Sheets-Sheet 14 Rack Ml lwll IMI F. sAco ErAL FLEXIBLE WEB TENSION CONTROL MECHANISM ,& Roll e -nr ns E 'ec 5 Rewin B iiQgLll Aug. 27, 1957 Filed Jan. 21, 1954 ATTORNEY Z,84,Z75 Patented Aug. 27, 1957 Felix Saco, Long Island, and Leonard Rockstrom, Manhasset, N. Y., assignors to Cameron Machine Company, Brooklyn, N. Y., a corporation of New York Application January 21, 1954, Serial No. 495,394

12 Claims. (Cl. 242-753) This invention relates to a flexible web tension control mechanism.

It is particularly directed to a mechanism for controlling the tension of a web of material as it is unwound from a mill supply roll and rewound by a rewind machine after cutting into the desired widths. The invention primarily relates to improvements in the compensating or tension control roll at the back of the rewind machine. This compensating roll is supported on springs at each end whose tension may be varied separately as desired. The strength of the springs is adequate to support the roll and its bearings. Hydraulic cylinders control the lift of the roll to supply the desired tension to the web of material entering the rewind machine. These cylinders may be adapted to supply the desired amount of resilience to the vertical movement of the roll occasioned by differences of tension in the web material. The ends of the roll are separately mounted and the bearings of the roll with its support are spherical to allow the ends of the roll to rise and fall unevenly.

Another object of the invention is to provide a synchronizing shaft connected to the supports of the compensating roll to apply a resilient pressure to the ends of the roll, to restore the roll to a horizontal position.

The invention also includes the floor stand idler roll with certain improvements in it, and the relationship of that roll with the compensating roll. The primary purpose of the floor stand idler roll is to receive the web of material from the mill supply roll, from which the web is fed with a varying angle as the size of the mill supply roll decreases and to pass it to the compensating roll at a substantially constant angle so that the tension on the web may be maintained substantially constant. The roll in the rewind machine which receives the web from the compensating roll and the floor stand idler roll is so positioned that the web in passing over the compensating roll has in it a bight or loop and the tension on the web is regulated by varying the length of that loop and as the position of the compensating roll varies, so may the speed of the floor stand idler roll be varied in proportion.

The invention is illustrated in conjunction with a rewind machine which is illustrated in Patent No. 2,743,879 of May 1, 1956, and reference may be made to that application for a detailed description of the parts of the machine illustrated herein which are not essential to an understanding of the present invention.

The above and other objects and advantages of the invention will be apparent from the following description and the accompanying drawings forming a part thereof, and in which:

Figure 1 is an end elevation of the mill supply roll, the floor stand idler roll and the rewind machine.

Figure 2 is a transverse vertical sectional view of the compensating roll in the machine.

Figure 3 is a rear elevational view of the left end of the compensating roll.

Figure 4 is a similar view of the right end of the compensating r011.

Figure 5 is a horizontal sectional view of the rear of the machine showing the compensating roll.

Figure 6 is a horizontal sectional view of the rear of the machine showing the support for the left end of the compensating roll.

Figure 7 is a vertical fragmentary sectional view through the left end of the rewind machine showing the com-' pensating roll mounting.

Figure 8 is a top plan view of the bell crank assembly at the left end of the synchronizing shaft.

Figure 9 is a vertical sectional view of this assembly.

Figure 10 is an elevational view of this assembly from the rear of the machine.

Figure 11 is a vertical sectional view of the bell crank assembly adjacent the center of the synchronizing shaft.

Figure 12 is an elevational view of this assembly from the rear of the machine.

Figure 13 is a fragmentary vertical view of the brake on the left end of the compensating roll.

Figure 14 is a fragmentary vertical sectional view showing the mounting for the brake shoe.

Figure 15 is a front elevational view, partly in section, of the floor stand idler.

Figure 16 is a vertical sectional view of the pump speed control attached to the floor stand idler roll.

Figure 17 is a fragmentary end elevation partly in section of the floor stand idler.

Figure 18 is a horizontal sectional view of the floor stand idler roll vertical adjusting mechanism.

Figure 19 is a fragmentary vertical sectional view of the brake at one end of the floor stand idler roll.

Figure 20 is a fragmentary elevational view of the valve control to vary the speed of the floor stand idler roll.

Figure 21 is a fragmentary elevational view of the pulleys and their supports for changing the direction of the travel of the cable leading to the valve control.

Figure 22 is a schematic view of the circuits for applying pneumatic and hydraulic pressure to the brakes and cylinders for controlling the elevation of the compensating roll.

Figure 23 is a schematic view of the hydraulic circuit for controlling the speed of the floor stand idler roll.

In the drawings similar numerals refer to similar parts throughout the several views. V

The continuous web 1 of material is removed from the mill supply roll 2 under tension and it passes under idler roll 3 of the floor stand 4 to the rewind machine 5. The rewind machine 5 has therein platen roll 6 under which the web passes and against which cutters 7 press to divide the web into widths after which the web is rewound by the rewind machine into the large roll 8.

The platen roll 6 and the floor stand idler roll 3 are of fixed height, the web passing under them and forming a loop or bight by passing over the compensating roll 9 in the rear of the rewind machine.

The compensating roll is not supported directly by the sides 10 and of the rewind machine, but is rather suppotred on two posts 11 at each end of the machine. These posts are supported on bars 12 at their lower ends which are rigidly screwed to the base of the machine and by bars 13 at their upper ends, which are attached to the side of the machine. On the posts or guides, 11 ride bearing housings 14 having therein spherical self-aligning bearings 15 supporting the ends 16 of the compensating roll 9. These bearings permit a limited angular movement of the compensating roll 9 in respect to the housings 14, so that one end of the compensating roll may be higher than the other end should the web of material run with one edge slack. The tilting of the compensating roll will permit tension to be maintained in the complete web should one edge run slack.

The separate housings 14 at each end of the compensatq ing roll and the roll itself are supported by Y yokes 17. These Y yokes consist of bars 18 connected at their upper ends to the sides of each housing 14 and at their lower ends to cross heads 19 sliding on rods 20 pivoted to the base of the machine brackets 21. Also pivoted to thebase of the machine at 22 are levers 23 which are forked at their upper ends and pivoted at '24-on both sides of each bar 18, the lever 23 forming onebranchof the Y yoke 17, and bar 18 the-other branchand the trunk of the Y. Sets of three compression springseach, -25,"are on each rod 20 hearing against the cross heads 19 and they are held on the rods by nuts; 26'and the degree of the tightening of the springs determines the vertical support furnished by them to the compensating roll 9.

Parallel to the compensatingroll 9, when it is'horizontal, and forward from it, is synchronizing shaft 30. This shaft 30 supports one end ofarrn'31 of a bell crank lever, the end being vertically forked "and having between its forks 32 and 33'block 34-keyed to the shaft by'key 35. Block 34 has in its opposite ends on each' sideof the shaft-30 bearings 36 having ro ds 37 screwed therein. The rods37 pass through bearings 38- mounted in openings in each side of forks 32 and 33-and compression springs 39 bear on these bearings 38 and against nuts '40 on the ends of the rods 37. By this construction vertical movements of arm 31 tend to rotate shaft -30'by bearing upon one of the springs 39. The other end of arm 31 is attached by pivot 41 to links -42-which in turn are attached to bracket 43 depending from plate 44 attached to housing 14 so that vertical movements of thehousing, and correspondingly one end'of compensating roll 9,tend to rotate the shaft 30.

Substantially centrally'located on shaft 30 is a torque resisting member-45 which is made fast to the shaft by tapered-pin 46, Fig. 11, and which has divided sides 47 between which pass bearings-48 which have holes in their centers and through which pass rods 49. These rods are fast inbearings 50 rotating in bracket SI-attached to a bar 52 extending across the back of the machine. Springs 53 are on the rods .49 and are held in compression by nuts 54. These springs tend to prevent rotation of shaft 30 The bell crank springs 39 -are initially tightened to transfer the vertical movements of the ends of the compensating roll 9 to the synchronizing shaft which movement is resisted by springs 53, and when these movements involve a greater movement at one end of the compensating roll than at the other, then a torque ortwisting moment is given to the synchronizing shaft 30. It willbe apparent, however, that any verticalmovement, whenthe springs are under adequate compression, transfer a corresponding rotary movement to shaft'30.

v Compensating roll 9 has extending ends 55 "attached thereto on which brakeshoes 56 of pneumaticbrake cylinders 57 bear. The brake shoes are mounted in cradles 58 pivoted to rock vertically at 59 and to rock horizontally at 60. The shoes are forced into braking position by pneumatic-pressure admitted to braking cylinder 57 by piston and 61 bearing against the other end of cradle 58. There aresimilar brakes at each end of the, compensating roll. These brakes are used only to stop rotation when the rewind machine is shut down. They are not usedto apply'drag to the compensating'roll to regulate tension on the web, to do so would burn them out, quickly.

The purpose of the floor stand idler is to maintain the angularity of the web'as it is fed to the compensating roll constant regardless of the size of themill roll. This idler is shown in Figures 18'to22 inclusive and it comprises the roll '3 mounted between two

stands

65 and 66. The self-aligning bearing for the roll in each stand permits angular adjustment of the height of one bearing in respect of the other. Theupper and adjustable portion of the roll supporting stand is provided as shown'with two aligning or positioning posts 67, which move upand .down in the-post guide bearings 68 in the bottom stav 4 i tionary portion of the stand 66. Also fixedly connected with this bearing mounting is screw 69 which has threaded thereon 'worm wheel 70 resting on horizontal bearings 71. Worm wheel 70 is turned by screw 72 to elevate or lower, the bearing on stand 66 to adjust the angular position of roll 3 to maintain the tension on both sides, of the web as near equal as possible, before the web passes to the compensating roll.

The floor stand idler roll 3 likewise has extensions'73 forming a brake surface forthe brake shoes 74 held in cradles 75 pivoted at 76 for vertical movement and at 77 for horizontal movement. Pneumatic brake cylinders-78 are mounted ontop of the stand housings, being alike on both stands and projecting therefrom is piston 79 to control the pressure of the brake shoe 74 on the floor stand idler roll 3. These brakes are vto stop theidler roll when the rewind machine is shut down. They are not for the purpose of placing tension on the. web. They are quite similar in construction to the pneumatic brakes 56 on the compensating roll.

Connected to the idler .roll 3 by a flexible coupling 80 is hydraulic pump 81 having pump gears'82 therein and orifices 83'for the connection thereto of hydraulic conduits; This pump 81 forces its fluid through'valve 84, the opening in which is varied by piston 85. i 1

Near the center of synchronizing shaft 30 is a projecting arm 86 having one end of a'cable 87 attached thereto. This cable initiallypasses over pulley 88 on bar 52 so that it may extend parallel with the synchronizing shaft until it-reaches pulley 89 where itsdirection is again changed to come to the rear of the machine where it passes around pulley 90 and ascends to be connected at its otherend to cylinder .91 which has therein piston rod 92 and spring .93 to give the piston rod a resilient movement in relation to the movement of the cable 87. Rod 92 passes through plate 94 on theback of the machine. The rod has nuts'95 at'itstop holding spring 96 between the nuts and plate 94 tending primarily to keep the cable 87 extended at all times. Plate 94 also has thereon bracket '97, pivoted to this bracket at 98 is lever 99 which has a fork 100 fitting over pin 101 on the rod92, sothat movements of the rod are communicated to the lover. The lever'at its other end has" an enlarged fork opening 102 therein which allows it to slide freely over. piston rod 85, but the opening is 'not'large-enough to allow the end of thelever-to slide over the nut 103 on the piston so that when the upward movement of the end 102 of the lever goes so far as to contact the nut103 the valve 84 is closed, substantially preventing the continued pumpingof fluid by pump '81 and stopping the floor stand idler roll 3. This action is, however, only an emergency action. Generally small movements are imparted by lever 99 bymeans'of lever 104 pivoted at 105 to bracket 97 and having in its operating end set screw 106 which bears upon the end of piston rod 85 to impart slightfmovementthereto to precisely regulate the speed of pump 81. To more precisely regulate this speed, lever 104' has thereon nut 107 which carries along/the lever roller 108 to bear upon lever 99, thus longitudinal movement of nut 107 imparts ever so minute adjustments to the "length of lever 99 so that the preciselydesired speed for floor stand idler roll 3 may be obtained.

As shown inFigure 22 filtered'air is fed to the line 109 under pressure. This air passes to line 110 connected to compensating roll brake cylinders 57 and idler roll brake cylinders 78 through solenoid valve 111 controlled by switch 112.

The air also passes through line113 by way ofuvalve 114. through pressure accumulator 115 to .the top and bottom ofbooster cylinder 116. The piston? of 'booster cylinder 116 is connected'to hydraulic line 117 which has fluid fed thereto from reservoir 118 through one way valve 119 and similar valve 120 to the bottom of the hydraulic cylinders'121 on bars 13, the pistons of which are connected to housings 14, serving to lift the compensating roll 9, there being one cylinder at each end of the roll. The tops of these hydraulic cylinders 121 have an air line 122 with a vent 123 to the atmosphere.

The Weight of the compensating roll and its bearings is balanced by the Y yoke linkages 17 and the springs of the support assembly. Air in the top of booster 116 may be set at a constant pressure with the vent from the bottom thereof open to the atmosphere and thereby the compensating roll is raised with a constant pressure by the hydraulic fluid, but always, of course, affected by the resilience of the air in the cylinder 116 on top of the piston. In the alternative the air at the bottom of the piston in cylinder 116 may be locked in the cylinder, by properly throwing the valve 124 and then the trapped air acts as a spring on both sides of the piston in cylinder 116 to regulate the lift of the compensating roll and therefore the tension on the Web. Due to the positioning and relationship of the air and hydraulic valves the compensating roll may move upward faster than it does downward, placing the web under greater tension faster, than relieving that tension. This throttling action is obtained largely through the adjustment of valve 125 which permits 'a rapid flow of hydraulic fluid to cylinders 121 but a very slow flow therefrom. At the lowest position of the compensating roll, with the springs set to support it and its bearings, more hydraulic pressure is required in cylinders 121 than in the upper, normally operating positions of the roll. This leads to a very stable condition for the roll, avoiding hunting and roll bounce. The hydraulic pressure in cylinders 121 likewise promotes this stability, and with this hydraulic pressure being applied by pneumatic pressure, great resilience as well as stability is provided.

Figure 26 shows the operating panel for the machine with the various levers operating the various parts of the rewind machine. The fluid supply tank 126 has a line 127 leading therefrom to the pump 81, then through valve 128, which upon proper adjustment passes the fluid to valve 84 for the automatic operation of the speed of the pump 81 as above described. Should this automatic operation not be desired the fluid can be passed through line 129 by proper operation of lever 130 on the valve. By adjustment of valve 131 the flow of fluid from the pump 81 may be set at a constant rate. When the valve 131 is functioning in this manner the fluid passes through line 132 to the valve, by proper adjustment of valve 128. The fluid passing through valve 128 in any of the directions above described returns through line 133 to the heat exchanger 134 which has a water inlet 135 and outlet 136 before the fluid passes back to the source or" supply at 137.

The edge tension take up of the compensating roll is not intended to compensate for continued uneven edge tension in the Web, this should be provided for by adjustments of the floor stand idler or even of the mill supply roll when necessary.

The operation of the compensating roll and its regulation of the tension on the web and the combination of that roll in controlling the web tension by means of controlling the speed of the floor stand idler roll will be clearly understood from the above detailed description. It will be apparent that many changes in the detailed construction of the mechanism for carrying out these purposes can be made without departing from the invention.

What is claimed as new and is desired to be secured by Letters Patent is:

l. A web tension control machine comprising, means to supply a web of flexible material, means to receive said material, a compensating roll between said supply and receiving means positioned to provide a tensioned loop in the Web, guides in the machine at each end of the roll, self-adjustable bearing mounting means for said roll at each end pivoting angularly to the roll axis, between the roll and guides, the mounting meansand roll moving bodily on the guides upon variations in the tension in the. material and each mounting means being mounted in the guides to move parallel to but independently of the other,

separate tension control means connectedto the mounting means at each end of the roll to maintain both edges of the web on the roll under tension, both when the web runs with equal edge lengths between the supply and receiving means and when it runs more full on one edge than the other, means to resiliently coordinate the application of the tension of said separate control means.

2. In a flexible web processing machine having a compensating roll around which a web of material passes forming a loop in entering the machine, under tension, a mounting for said roll comprising spaced guides in the machine, self-adjustable bearing means pivoting angularly to the roll axis connecting the roll at each end between the spaced guides and each bearing means being mounted in the guides to move parallel to but independently of the other, separate tension control means connected to the bearing means at each end of the roll to maintain both edges of the Web under tension to enlarge the loop in the web, both'when the Web runs with equal tension at both edges of the web and when it runs with unequal tension at the edges, and means connecting the bearing means at both ends of the roll constantly tending to restore the roll to a position normal to the direction of travel of the web upon its displacement therefrom.

3. In a flexible Web processing machine having a compensating roll around which a Web of material passes forming a loop in entering the machine under tension, a mounting for said roll comprising spaced guides in the machine, self-adjusting bearing means connecting the roll at each end to and between the spaced guides, supports for each said bearing means extending angularly from the ends of the roll and toward each other, springs extending substantially parallel to the roll connected to said supports to urge the roll to web supporting position normal to the direction of web travel.

4. The machine of claim 3 including means connecting the bearing means at both ends of the roll constantly tending to restore the roll to a position normal to the direction of travel of the web, upon displacement therefrom by the Web.

5. In a flexible web processing machine having a compensating roll around which a web of material passes forming a loop in entering the machine under tension, a mounting for said roll comprising spaced guides in the machine, self-adjusting bearing means connecting the roll at each end to and between the spaced guides, supports for said bearing means at each end of the roll, resilient means connected to the bearing means at each end of the roll to urge the roll to extend the loop in the web and support the roll in a position normal to the direction of Web travel, a synchronizing shaft parallel to the roll and connected to the bearing means at each end of the roll, and means on the shaft to return the roll to a position normal to the direction of web travel upon displacement therefrom by the web.

6. In a flexible web processing machine having a compensating roll around which a web of material passes forming a loop in entering the machine under tension, a mounting for said roll comprising spaced guides in the machine, self-adjusting bearing means connecting the roll at each end to and between the spaced guides pivoting angularly to the roll axis, independent fluid pressure means at each end of said roll connected to said bearing means to move the roll vertically to vary the tension on the web at each end substantially equally whether the roll be normal to the direction of Web travel or not, a synchronizing shaft substantially parallel to said roll and connected to the bearing means at each end thereof, both said fluid pressure means, upon adjusting the pressure, and said shaft, tending to restore the roll to a position nortrial to the direction of web travel "u'pon'its displacement therefrom. a

t 7. A flexiblewebtension controlmechanism comprising, a web processing, machine having thereina'icompe'nsatingtroll, a mill supply roll and an idler roll, said machine, mill supplytroll. and idler roll being positioned to pass a web under tension from the mill supply roll under the idler roll and over the acompensatingi roll, the compensating roll forming a vertically extending loop, in the web, verticallymovable supports in the machine connected to the ends" of the compensating roll to support the same, web tension control means. at :the ends of the compensating roll to raise 311d.1lOW6I' the compensating roll,,means toregulateithe' speed of the idler roll, means connected to the compensatingroll actuated by the verti'- calmovemen'ts of said roll connected to the idler roll speed regulating means to vary the speedof the'idler roll upon vertical movement of the compensating roll..

8. Thelmechanismflof claim 7 in which the idler roll speedlregulating means comprisesia fluid pressure pump connectedto the idler roll, a valverin the line from the pump the opening of which varies thespeed of the idler roll, the valvebeing actuated by the said means connected to the compensating roll,

9. In a fiexiblewebtprocessing machine having a compensatingroll around which a webof material passes forming a loop in entering the machine under tension, an idler roll around which the web passes before entering said machine, a mounting for said compensating roll comprising spaced guides in the machine, self-adjusting bearing means connecting the roll at each end to and between the spaced guides, separate means connected to the hearing means at each end of the compensating roll to vertically support the bearing means and roll, meansconnecting the bearing means at both endsof the compensating roll constantly tending to restore thetroll to a position normal to the direction of travel of the Web upon its displacement therefrom, the restoring means being moved by vertical movement of the compensating roll, means to regulate the speed of the idler roll, means connecting the compensating roll restoring means to the idler roll speed regulating means to vary the speed of the idler roll by variations of the elevation of the compensating roll.

10. In a flexible web processing machine having a cornpensating roll around which a web of material passes forming a loop in entering the machine under tension, an idler roll around which the web passes before entering said machine, a mounting for said compensating roll comprising spaced guides in the machine, self-adjusting bearing means connecting the roll at each end to and between the spaced guides, separate means connected to, the bearing eans at eali end of the compensating roll tovertically from by the web, the shaft being moved by vertical movement'of the compensating roll, means to regulate the speed of the idler roll, means connecting said last named means to said shaft to vary the speed of the'idler roll by vertical movement of the compensating roll.

11. The mechanism of claim 10 including means, on the synchronizing shaft to'relieve the shaft from torsional strain and restore the compensating roll to a position normal to the direction of 'web travel and in which the idler roll speed regulating means connection to the shaft is substantially at the center thereof, to reflect the height of the compensating roll when the-ends are unevenly elevated. i

12. In a flexible web processing machine having a compensating roll around which a web of material passes forming a loop in entering the machine under tension, an idler roll around which the web passes before entering said machine, a mounting for said compensating roll comprising spaced guides in the machine, self-adjusting bearing means connecting the roll at each end to and between the spaced guides, separate means at each end of the compensating roll to vertically support the bearing means and roll, a synchronizing shaft parallel to the compensating roll and connected to the bearing means at each end of the compensating roll, said shaft constantly tending to restore the compensating roll toa position normal to the direction of web travel upon its displacement therefrom by the Web, the shaft being moved by vertical movement of the compensating roll, a fluid pressure pump connected to and drivenby the idler roll, a valve in the feed line from said pump, the opening of which regulates the fluid pumped by the idler roll, means connecting said valve to said shaft to vary the speed of the idler roll upon vertical movement of the compensating roll.

References Cited in the file of this patent UNITED STATES PATENTS 131,103 Kearney Sept.v 3, 1872 1,100,039 Tyler et al. June 16, 1914 1,380,837 Replogle June 7, 1921 1,652,299 Carpenter Dec. 3, 1927 1,825,966 Laycock Oct. 6, 1931 1,929,087 Wood Oct. 3, 1933 2,105,824 Simonds Jan. 18, 1938