US2190379A - Web tensioning mechanism - Google Patents

Description

Filed May 1, 1936 3 Sheets-Sheet.1

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Feb. 13, 1940. A. J. HORTON WEB TENSIONING MECHANISM Filed May 1, 1936 3 Sheets-Sheet 2 INVENTOR. Wfij Feb; 13, 1940. A. J. HORTON WEB TENSIONING MECHANISM Filed May 1, 1936 3 Sheets-Sheet 3 R O T N E v m Patented Feb. 13, 1940.

UNITED STATES was TENSIONING MECHANISM Albert J. Horton, White Plains, N. Y., assignor to B. Hoe & 00., Inc., New York, N. Y., a corporation of New York Application May 1, 1936, Serial No. 17,308

18 Claims. (01. 24275) This invention relates to a web tensioning or feed control mechanism'for use with machines operating upon a web and has especial reference to tensioning mechanism for the paper web running into printing machines of the high speed In machines of this type, a web supply mechanism having a rotatable reelfor supporting a plurality of web rolls is provided. The arrangement in the web supply mechanism is such, that when the web running into the machine from the running web roll is substantially removed froin the roll, the reel is rotated to dispose a replacement web roll in position to have its web joined to the running web. While running at its original position, the tension of the running web may be governed by a web roll control mechanism which acts upon the roll through a-driven endless belt, and which is controlled by a roller disposed in a so loop in the web, as it runs into the machine. The roller is generally supported upon arms, which upon swinging due to the lengthening of the web loop upon a decrease in web tension, or the shortening thereof due to an increase in web tension, causes the actuation of mechanism provided to compensate for these differences in tension and a web tensioning mechanism of generally immaintain the web tension substantially uniform. Mechanism similar to that shown herein for maintaining the tension of a web running from 80 a roll, by the use of an endless driven belt, is shown and fully described in Patent 2,155,430.

Under certain conditions, it is desirable to vary or regulate the tension on the web running into the machine and this may be accomplished by 86 the provision of a counterweight which is adjustable along an arm connected-to the arm supporting the roller disposed in the web loop. To avoid abrupt-movement of the roller supporting arm should the machine he suddenly stopped or 40 if the running web should break, a dash pot may be, provided in connection with the roller sup porting arm. Mechanism as referred to above, wherein an adjustable counterweight is used and a dash pot is provided, is shownand fully described in Patent Number 1,881,589, dated October 11,1932.

When the running web roll approaches exhaustion and the lead of the web is to be changed 'to draw paper from a replacement roll, the running roll is moved out of contact with the belt and it is, therefore, necessary to provide a device for maintaining the required tension on the web as it continues to run from the roll. A manually adjustable brake device acting directly uponthespindlecarryingtherollisinuseand under the control of the tension on the running illustrated has proven satisfactory in most instances, but is inconvenient in some respects, as it requires attention and occasional adjustment, as changes in roll diameter cause variations in the web tension.

This invention contemplates, as its principal object, the provision of a web tensioning mechanism .which is controlled by a roller disposed inf a loop of the web as it runs into the machine and which will automatically maintain the ten- 10 sion of the web substantially uniform when the running web roll is in any of its reel supported positions. I

Another object is to provide a web tensioning mechanism controlled by a. roller running in a 1 loop in the web and'which,-while under such control, acts directly upon the web to compensate for variations in the tension thereof.

Still another object is to provide in a web tensioning mechanism adapted to produce a drag 20 on the web a driven roller over which the web runs and means to press the web against the driven roller with varying degrees of pressure.

web. 25

It is also an object of the invention to provide proved construction, whereby the device will be simple, durable and inexpensive in construction, as well as convenient, practical, serviceable and Q0 eflicient in its use.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of con- 85 struction hereinafter described and claimed.

The preferred embodiment'of the invention is in the accompanying drawings, wherein:

' Figure '1 is a side view of a web supply mecha- 4o nism for a printing machine, with a web tensioning mechanism, constructed in accordance with the principles of this invention, applied thereto; I

Figure 2 is an enlarged side view of a portion of 5 the mechanism shown in Figure 1;

Figure 3 is a face view of the mechanism shown in Figure 2- looking in the direction of arrow 3 thereof; and

Figure 4 is a diagram showing the control circults of the tension controlling motor.

The web supply mechanism shown in the drawings is of the type referred to above, wherein a rotatably mounted reel I I is provided, having provision in the form of arms I2, 13 and I4 for sup- 88 .provided a driven belt l8 led about pulleys I9,-

2| and 22, the pulley 22 being mounted upon the end of arms 23 secured to a rockable shaft 24,

and the pulley 9 being drivingly-connected to a shaft 25 bybevel gears 29'and 21. The shaft 25 may be drivingly connected with a driven part of the machine and arranged to drive the belt i9 preferably at a speed slightly less than that of the web '28 running into the machine. A gear segment 29 secured to the shaft 24 has a pinion 3| in mesh therewith, the pinion 3| being secured upon the shaft of a motor 82. Suitable control mechanism for operating the motor in either direction, is enclosed in a casing 33, and is arranged to be actuated by a reciprocable rod 33, slidable in response to. variations in the tension of the running web 28, by being connected to and movable with arms 35, which are secured" to ashaft rotatably supported in fixed bearings. The arms 35 support a roller 39 disposed in a loop of the running web.

The roller 39 may be counterbalanced by a weight 31 slidably mounted upon a rod 38 and adapted by means of tongues 39 to be positively located in various positions along another arm 6| secured'to the shaft 35' and movable with the arms 35, the tongues 39- engaging in notches 62 formed in the arm ,4|. A spring 43, secured atone' end to a machine frame part 44, reacts against the arms 35 through connection therewith comrected with the other end of the spring 43 and an arm 35, and constantly tends to urgethe roller 39 away from the web 28. The 9.1"-

rangement is such that the combined action of the roller 39, the weight 31, and the spring 43 will impose a suflicient pull upon the web to maintain it taut, and under the desired tension.

Electrical connections for controlling the motor 32 by means of the control switches mounted within the casing 33 are shown in Figure 4, and it will be understood that-an excess of tension on the web running to the machine will raise the roller 39'and move the rod 34 towards ythe right, whereupon switch 9| will be swung to make connection with contact 82, thereby closing a circuit that may be tracedfrom line LI through conductor ,83, solenoid 84, conductor 85 to conta'ct 82, through switch 8| and conductor89 to line L2, thus energizing solenoid 94 andestablishing a circuit through motor 32, that may be traced from L| through conductor 83, switch 81- (then closed), and conductors 88- and 89 to the motor 32 and from the motor by conductors 9| and 92, through switch 93,

through conductors 94 and 89 to L2,-and assuming the motor 32 to be a three-phase alternating currentmotor, line L3 will be connected ,directly .to the motor by conductor 95. Thus energizing the motor will cause it to rotatein;

a direction to decrease the wrap of the belt i8 about the roll l9, and thereby reduce the -tension on the web running to the machine;

the motor to rotate in the opposite direction Should the tension on the web become insumcient, the floating roller 89' will descend,-

thereby moving the arm 34 to the left and closing the switch 99. .This will energize the sole- .noid 91 and complete a circuit thatwill cause andthe'reby increase the wrap of the-belts l9 about the roll I9 and impose additional drag 5'9 ontheroll, therebyincreasing the on mains stationary.

by means of another arm 45, which isweb thereof.

constituted by a brake band 48 in frictional "en-=7 the web. Circuits thus established may be traced from Ll through conductor 93 to solenoid 9.1

and thence conductor 98 to contact 99' and through switch 99 and conductor 89 to line L2.

Solenoid 91 thus being-energized, the switches 5 '|0| and |92 will be closed, establishing acircuit to the motor, that'may be traced from lineL-l, switch |8| and conductors 92 and .9| to the motor 32,'and from the motor by conductors,

89 and 99,.thr0ugh switch I82 which is connected to line L2. When the correct tension is being applied tothe web, neither switch 9| or 99 isclosed and the rotor -of the motor 32 re- By means of the above described mechanism, the tension on a web running from a roll disposed in the position of roll l9, will be main tained substantially uniform, the belt arm 23 being swungv by the motor 32 under control'of the mechanism in the casing 33 toincrease or decrease the wrap'of the belt l8 about the roll l9, and restrain or permit freer rotation of the; roll in response to movement of the floating roller. A dash pot, not shown, may be provided in accordancewith the construction shown in the patent above referred to, if- 'so desired, to prevent abru t movement of the arm 35. When the 1011 I9 nearly exhausted, the reel H is rotated toposition the rolls, l5 and |9,.as shown in Figure'l, wherein the roll I9 now becomes 30 the replacement roll and the roll i5 is the roll from which the web is expiring. The belt l8 now acts by engagement with the replacement roll to bring it up to web speed, whereupon a web deflector 'or brush 49 may be actuated in a known manner to press the web against the roll l9' to join it by means of adhesive to the When the roll I5 is moved out of control of the belt l9, the tension on the web may be 4Q controlled by a manually actuated device acting upon a spindle 41 engaging the core of the web roll and which is herein shown'as beinggagem'ent about and with a brake drum 49.se--

cured to the spindle 41; Bymeans of an ad-' justing, wheel- 5|, the amount of braking friction may be controlled so that the desired web tension maybe substantially maintained while a replacement roll is being brought into position and its web joined to the running web 28.

Although the mechanism about to be described is primarily intended to autqmatically maintainthe tension on the web running, from a web roll l5 positioned as shown, it also may be in operation to assist the belt "in maintaining a uniform tension on a web running from the roll l9. It will also efllciently operatev in cooperation'with the manually adjustable ten 00 sion device abovedescribed and will efllciently maintain a substantially uniform tension on the V runningweb without either thesbelt II or the manually adfustable tension device being in use;

ing the features of this invention includes arms 52 (see Figures 2 and 3) Secured to the Shaft 35' and movable with the arms 35, each arm- 52 having a cam roller 53 carried by its free end, and which is disposed in a cam-slot 54. formed in the .free end of each of a of =H erein the web tensioning mechanism embody- 85.

when the arms 52 are swung with the arms 85, under influence of the web l8 upon the roller 85.

The web 28 from either the replacement roll I5 or the expiring web roll I5 is directed into the machine by being led over roller 58, under roller 58, over roller 68, looped under the roller 88, and thence over the rollers-5i and GI and to the machine.' As'the web passes over the roller 58, it is engaged by a roller 52. The roller 58 is driven at a speed slightly less than that of the running 'web, by being drivingly connected to the shaft 25 for instance, by means of sprockets 83 and 84 respectively connected to shaft 55 of the roller 58 and shaft 85 of the pulley l8, which is connected to the shaft 25 through the bevel gears 28 and 21. A chain 81 connects the sprockets and 84. The roller 62 is mounted for free rotation upon the outer end of arms 88, which are supported on and suitably secured to the shaft 58. Springs 89 each connected at one end to an arm. 88 and at its other end with a lever 55 connect these parts, whereby movement of the levers 55 upwardly will pull the roller 82 through the springs 68 away from the roller 58 and release pressure thereof against the web 28 running over the roller 58 and permit the web to slip; and movement. of the levers 55 in the other direction will permit the roller 82, due to its weight, to press the web 28 into firmer contact with the roller 58 and impose increased tension on the web by tending to retard its speed.

The roller 82 is preferably made of a non-.

metallic material, such as rubber, to reduce the noise of its engagement at high speed, with the roller 58, and the springs 88 may act as a resilient connection between the arm 58 and lever 55 to cause the movements of the roller 62 to be dampened. An arm 1|, having a handle I2 secured thereto is pivoted on a screw stud 13, secured to one of the arms 88 and in axial alignment with the roller 82. The arm H is adapted to be rocked by the handle 12 into the position shown in dotted lines in Figure 2 whereby its cam end 18 will rest upon the extended end I5 (see Figure 3) of the roller 58 disposed beneaththe same, and separate the roller 82 from the roller 58, for the purpose of threading a web therebetween and into the machine when the machine is stopped. Upon starting the machine, the roller 58 is rotated, the arm Ii rides off the extended end 15 of the roller and allows the roller 82 to engage the web on the roller, 58, and due to the weight of the handle 12, swings into the full line position, shown in Figure 2. If desired the cam 14 may be arranged to engage the shaft of the roller 58 instead of its periphery or it may engage a separate wheel rotated with the shaft. ,"By the provision of the above described web tensioning mechanism, the tension on the web 28 will be maintained substantially uniform during the interval the web roll I5 is out of engagement with the belt i8, when preparing and disposing the web supply mechanism in readiness for'joining a running web to the web of a replacement roll. When a web tensioning mechanism 'of the above nature is in operation in conjunction with the belt l8, that is, when a web is running from a roll positioned at l8, it acts as an auxiliary web tensioning device assisting the belt I8 and its controls, to maintain the web tension uniform. The manually adjustable tensioning device, above described, may be used to v advantage with the web tensioning mechanism of this invention. Thisis accomplished by setting the manually adjustable device to impose the required friction upon the roll I5, when the web is practically exhausted therefrom, whereupon the action of the rollers 58 and 82 upon the web 28 need compensate only for variations in web tension occurring while the web, remaining on the roll l5 after its removal from the influence of the belt i8, is running off from the roll. Should occasion arise, where the use of a belt l8 and the manually adjustable tensioning device, both of which act upon the roll, are dispensed with, the web tensioning mechanism of this invention, which acts directly upon the run-v ning web, is capable of efflciently maintaining the tension on the running web substantially uniform.

It will be understood that the invention may be embodied in other specific forms without, departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, and it will be further understood that'each and every novel feature and combination present in or possessed by the mechanism herein disclosed forms a 'part of the invention included in this application.

What I claim is:

1. In a web tensioning mechanism, a roller against which a running web is led, means to drive said roller at a speed slightly less than the speed of the running web and in a direction to feed the web in the same direction as' the web is running, a swingable roller arranged to engage the running web and press it against said driven roller whereby a drag will be imposed by the driven roller upon the web, and means infiuenced by variations in the web tension to control the swinging of said swingable roller to vary the degree of pressure imposed thereby and the drag of the driven roller upon the web.

2. In a web tensioning mechanism for a machine operating upon a web and into which the web is being drawn, a roller driven slower than the speed of the web and against which the web is led and over which it may slip, a second roller disposed in a loop of theweb to be moved thereby under influence of variations in web tension, and means actuated by the movement of the..second roller to, cause the running web to engage the driven roll at the degree of pressure required to impose a braking action of the driven roller. upon the web to maintain the web tension substantially uniform.

3. In a mechanism for controlling the tension of a running web, a first member driven to move in the direction of, and at slightly less speed than that of the running web, a second member arranged to press the web against said first member to cause a drag to be imposed upon the web by said first member, and means influenced by ing rollers between which a running web is dis-- posed, the first of said rollers being driven at slightly less speed than that of the running web,

said driven roller being driven to rotate in a 7 direction to feed the web in the same direction" that it is running, the second of said rollers being movable to press the runn ingweb againstthe first roller to cause a drag to be imposed on the web, and meapsdnfiuenced by variations in 1 tension of the web after it has passed said rollers to move said second roller and vary the drag imposed on the web.

5. In a web tensioning mechanism, a first rotatable member disposed in a loop in a running .web and. movable in response to variations in the web tension, a second rotatable member over whichthe web runs and against which it is pressed to impose a braking efiect on the web, and means actuated by movement of said first member to vary the degree of pressure of the web on. said second member.

the web.

7. In a tension control mechanism for a web being drawn into a machine whereby it is operated upon, a pair of rollers between which the web is pressed, movable bearings for one of the said rollers, means for driving one of the rollers in timed relation with the machine and at a peripheral speed somewhat slower than the speed of the web to adapt it to impose a drag thereon, a floating roller running in a loop in the web, and means connecting the floating roller and the movable bearings, whereby any movement of the floating roller due to variation in the length of the loop will simultaneously vary the pressure of the said pair of rollers against the weband the resulting drag thereon.

8. In a tension control mechanism for a web being fed to amachine whereby it is operated upon, a first roller and a second roller between which the weo is normally pressed, means for driving the first roller in timed relation with the machine, movable bearings for the second roller whereby it may be moved away from the first roller, a cam operably connected to'the second roller and adapted to engage the first, roller, the

said cam being movable to hold said rollers separated when'they are not rotating and rendered inefiective to maintain the separation, when the flrstroller starts to rotate.

9. In a web feed control mechanism for a web being. fed to -a machine by which it is operated upon, a first roller and a second-roller between which the web is normally pressed, means for driving the first roller in timed relation with the machine, a movable. support for the second roller whereby it may be spaced from the first roller to facilitate threading a web therebetween, an engaging surface rotating with the first roller, and a separating element operably connected to the movable support and adapted to engage the engaging surface; the said separating element being movable to hold said rollers separated when they are not rotating and automatically rendered inefiective to maintain the separation, when the first roller starts to rotate.

10. In -'a web feed control mechanism for a web being fed to'a machine by which it is operated upon, a pair of rollers between whichthe web is normallypressed, means for driving one of the rollers in' timed relation with the machine,

' a movable support for one of the rollers whereby it maybespaced from the other roller to facilitate a web between them. and a separating element movable to operative position to space one of the rollers from the other roller; said separating element being automatically movable to inoperative position when the machine starts.

11. In a mechanism for controlling the tension of a web running from a web roll mounted upon a rotatable supporting spindle, a manually controlled brake on said spindle adapted to apply a braking action thereon 'to cause a drag on the running web, a first rotatable member driven at less speed than that of the running web, said driven rotatable member rotating in a direction to feed the web in the same direction that it is' running, a second member movable to enga e and press the web against the first member to cause a drag to be imposed on the running web,

and means influenced by variations in the tension of the running web after it pwses said first member to vary the degree of pressure imposed upon said web by said second member.

12. In a web tension device for a machine operating upon a web running ctrom a web roll, in combination, a driven belt the periphery of the web roll and constituting a brake for said roll, a driven roller over which the web -is led after it leaves said roll, said driven roller rotating in a direction to feed the web in the same direction that the web is running, said belt and said roller beingdriven at slightly less speed than that of the web, means to vary the wrap of said belt about said web roll, means to press the web against said roller, and a roller running in a loop in the web adapted to vary the web pressing movement of said web pressing means, tomaintain substantially constant tension on the web running into the machine.

13. In mechanism for controlling the tension of a running web, a rotatable member over which the web runs and which is'driven at less speed than the running web, said rotatable member rotating in a dii'ection to feed the web in the same direction that it is running, a movable member arranged to prws the web against the rotatable member to cause a drag to be imposed upon the web by said rotatable member, and means actuated by variations in web tension to move said movable member.

14. In a web tension mechanism for a machine operating upon a web drawn Irom a roll and in which running web 'rolls are successively moved from a normal running position to an exhausting position preparatory to joining the web of an expiring roll to the web of a replacement roll without stopping the machine, in combination, means for rotatably supporting a plurality of web rolls that are moved successively to running and exhausting positions, a first braking means operable on a web roll in running position to control tension on the web running therefrom, a second braking means operable" directly on the web running from a web roll that has been moved to exhausting position, a floating roller running in a loop in the web, and means operably connecting the floating roller with the first braking means and the second braking means to automatically maintain a desired web tension.

15. In a web tensioning mechanism for amachine operating upon'a web running from a web roll, in combination, a roller driven at a speed less than that of the running web, said driven roller having the web in contact therewith and rotatinginadirectiontofeedthewebinthe same direction as the web is-running, a freely rotatable roller arranged to press the running web against the driven roller, a driven belt mov the tension oi the running'web, a roller driven ingataspeedlessthantheperipheralspeed of said web roll and engaging the web roll to cause a braking action thereon, means to vary the wrap of the belt 'upon the web roll to vary its braking action, and means influenced by vari-' ations in the tension of the running web to vary the degree of pressure imposed upon the running web by the freely rotatable roller.

16. In a web tensioning mechanism for a machine operating upon a web running from a web roll, in combination, a roller driven at less speed than the web over which the web is led and may slip, a freely rotatable'roller arranged to press the running web against the driven roller to apply a drag on the web, a manually adjustable friction applying device acting on the web roll to cause tension on the web running therefrom, and means influenced by variations in the tension on the web to actuate said freely rotatable roller to vary the degree of on the running web by said driven roller.

1'1. In a web tension control device for a machine operating upon a web running from a web roll, in combination, a driven, belt moving at a speed less than the peripheral speed of said web 1 roll and emglng the web roll, means to vary the wrap of said belt upon the roll to control at less spe d than the running web and over which the web is led as it leaves the'web roll, said driven roller having the web in contact therewith and rotating in a direction to feed the web in the same direction as the web is running, a second roller arranged to, press the web against said driven roller, means to vary the degree of pressure imposed bysaid second roller upon the running web to control the ten-.

sion thereof, and means influenced by the tension of the web as it enters said machine toactuate one of the aforesaid tension controlling means. 18. In a web tensioning mechanism, a roller around which a running web is led and driven at less speed than the nmning web, a swingable roller arranged to press the running web against said driven roller, means influenced by variations in the tension on the running web to. vary the degree of pressure imposed by said swingablt. roller upon the web, and means movable in one direction into position to separate and hold said rollers separated when said web is stopped and arranged to move into another position to permit the rollers to move together when the web is started. i

AIBERT J. HORTON.

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