US2417447A - Cloth guider - Google Patents

Description

March A18, 1947.k

J. D. RoBRTsoN cLTH GUIDER Filed nay 17, 1945 4 Shee'ts-Sheet 2 18, 1947. J D, ROBERTSQN I 2,417,447

CLOTH GUIDER Filed lay 17, 1945 4 Sheets-Sheet 3 March 1s, 1947.

'.J. D. ROBERTSON CLOTH GUIDER Filed May 17, 1945 4 Sheets-Sheet 4 y Patented Mar. 18,1947

CLOTH GUIDEB John D. Robertson, Taunton, Mass., assigner to Mount `Hope Machinery Company', Taunton, Mau., a corporation of Massachusetts Appuemenmy 11, 194s, serial Ne. 594,325

(ci. ze-s'n 21 Claims.

'I'his inventionrelates to improvementsin cloth guiders and more particularly to that class of cloth guiders which are self-acting to correct selvage deviations, as distinguished from the relatively more complicated and more expensive cloth guiders which require the intervention of an exterior power medium, such as electricity,y compressed air, and the like, for controlling the selvage correcting means.

Cloth guiders of the general type to which the invention relates ordinarily have tiltable pairs Y of rolls which engage opposite selvage regions of a travelling web of cloth, and each pair .of rolls is responsive automatically to change the degree of tilt of the rolls whenever the engaged selvage region of the web departs from a predetermined transverse relationship to the center-line of travel of the web. The respective pairs of rolls are separately tiltable in parallelism with the plane of the web engaged thereby so that a transverse,

traction or repulsion can be exerted by the rolls on the cloth which' traction or repulsion is varied by increase or decrease of the angle of tilt of the rolls relative to a plane at right angles to the plane of the travelling web. e

It is among the objects of my present invention to provide a tiltable-roll selvage guider embodying features of structural simplicity and sensitivity of operation not possible of attainment in prior selvage guiders of which I am aware. I employ a novel principle of selvage control whereby tilting of the rolls as a result of departure of a selvage from a predetermined course is responsive to frictional engagement of the selvage with a rotary element which, in one form, continues fixed in its position of rotation regardless of the positions of the rolls as regards theirdegree of tilt, and which, in another form, moves with the rolls as the latter tilt. l

Another object is to minimize frictional resistance to tilting of the cloth-engaging rolls whereby to attain a superior degree of sensitivity of control-of a selvage. According to the invention a selvage moving outward between thev rolls As a result, v

2 of a selvage region of web with a drag-increasing portion of a roll or an element or elements carried on the tiltable roll unit.

A further object is to provide means for adjustment of the sewage-engaging means as the diameters of the web-engaging rolls decrease due to wear. y

Yet another object is to provide adjustable tension means which acts on a tiltable roll unit and which yieldably resiststilting of the unit in response to seivage departures, and means for adjusting the torque while the machine is in operation.

Still another object is to generally improve the structure and operative eillciencyw of tiltable-roll selvage guiding structures as compared with prior selvage guider proposals.

-tailed description of one mechanism will It is, mereov'en'my intention that the patent shall cover, by suitable expression in the 4appended'claims. whatever features of patentable novelty exist in the invention disclosed.

In the accompanying drawings:

Figure 1 is a top plan view of a tiltable cloth guide mechanism embodying features of my invention;

Figure 2 is la side elevation of the mechanism of Figure 1 with portions broken away:

Figure 3 is an end elevation looking at the right hand end of the mechanism of Figures l and 2:

Figure 4 is a cross-sectional view on line 4-4 of Figure 2;

Figure 5 is a front elevation-showing the Figures 1-4 form of my improved cloth guiding units in their positions of maximum tilt, as when no cloth is engaged between them; y

Figure 6 is a face view of a modied form of sewage-engaging wheel, its shaft being shown in cross-section;

Figure 7 is a cross-sectional view on line 'I4-'i of Figure 6, on a larger scale;

Figure 8 is a view similar to Figure 1, but showing a modiiied-form'in which the peripherally 4mechanisms,r as seen 'in Fig. 5, are designed to serve respectively at the right` and left sides of the machine but otherwise will be substantially the same in structure and operation, and a debe equally applicable to the other.

Referringto Fig. 1,` each mechanism comprises a pair of rolls indicated generally at l0 and I2 carried on a swinging arm I4 whose pivotal axis I6 is on a base I8 which is adapted for securement to a member 20 (Fig. 5) which is adjustable on the bar 22 extending from side to side of the machine. The rolls I0, I2 are illustrated in an arrangement for co-action with a web which travels downward in a'vertical plane. If it be desired that the web travel upwardor that. itapproach the guide rollsin a horizontal f plane orin anyv inclined plane between vertical and horizontal. the illustrated mechanism and co-acting elements would be correspondingly shifted and altered for effective co-actionwith the web, with suitable springs o r other mechanical means adjusted to act on the tiltable unit in conjunction with or in absence of gravity as any particular embodiment may require.

In the embodiment herein represented, the axis I6 of the roll-carrying arm I4 is at right angles to the plane of travel of the web to the rolls, and is located in rear of the rolls at a midlocation along their extent and in the horizontal plane of the axes of the rolls. Arm. I4 extends from its axis in general direction parallel with the plane of the web at the rear side of the latter and, at a location beyondthe outer ends of the rolls, the arm I4 turns sharply forward and has vthe forwardly extending part I4' on which the .rolls are mounted, the roll IIJ having a fixed axial support on arm extension I4' and the roll I2 being. mounted in a bracket 2| toward the forward end of the extension I4', for movement towardand from roll I8 about an axis 24 which f is' parallel with theaxls of roll lz and adjustable onitsblock bearing 26 by means o f set screw 28 andclalilping screws villi.- A coil spring 32 holds lroll I2 resiliently in contact withroll Ill `or with; a web'of cloth engaged between the rolls. SpringI 32 has one endanchored at 34 on arm I4 and has f its other end engaged around the headed end of a screw 36 whichextends through anearv38 on bracket 2|, withy a wing nut 40 on the threaded end of the` screw for adjusting the tension of .K

spring 32. ,e

Preferably, when the rolls are spread out of contact witheach other, the axis of roll I2 will be slightly out of parallelism with the axis of roll I0, with the inner unsupported end of roll I2 -a little closer to roll I0 than its supported end,

so that, when the rolls aredrawn together by spring 32, their inner end portions first contact each other, or a web of clothy engaged'between them. If theroll axes initially were parallel, there would be a tendency for the rolls to engage at their outer supported endsand for their inner unsupported ends to be sprung a little away from each other, due to the having of a single support for each roll at its outer end. By having the roll I2 initially canted slightly toward roll IU, there is assurance that the inner ends of the rolls will be in relation to effectively grip a web between them. Yet the outer end of roll I2 also is drawn by spring 32 into gripping relation, possibly with a slight springing of the support, so that pressure betweenl the rolls approaches uniformity throughout their lengths, or it may be that the pressure between the rolls continuesto be a little greater at their inner un- Suliportedends. K

.Rolls I and I2 may be of any usual or desired construction but I'prefer to employ rolls which V have surfaces of rubber or the like.

.According to my invention, a.A shaft 42l is mounted below the outer ends of rolls I0, I2 and transversely of the rolls. In what I at present 4 K i Y. 'consider to be a preferred form, as shown in Figs. 1-5,'the shaft is mounted in a frameY piece 44 which is secured as at 46 to the base I8, whereby the frame piece 44 and the shaft remain xed in position when-ann swings to tilt the rolls IIJ, l2. Frame piece v44 extends. outward generally parallel with the rolls at. the rear thereof and then forwardly below the forward extension I4' shaft 42 extends and in which the shaft is /mounted. Each bearingl portion 48.156 has a ball-bearing unit 52 therein in which reduced ends of the shaft 42 are journalled, so that the shaft is freely rotatable with a minimum of frictional resistance. I

Adjacent the rear" ball-bearing unit 52, shaft 42 has the longitudinally extending teeth V54 therein in mesh with the teeth 56' of a gear segment 58 mounted on the roll-carrying arm 'I4 which itself is mounted on anti-friction ball-bearings as at 60, forswinging movement about its axis at I6 with a minimum of frictional resistance. r

Toward the forward end ofv shaft 42, a periphso that the wheel and shaft rotate as a unit. As

herein represented, the wheel comprises two dished sections clamped together on the threaded forward end of shaft 42 -by the clamping nuts 64, 66 on opposite sides of the wheel. In the form as shown in Figs. y1-4, the peripheral groove 68 ln the wheel has substantial depth land has slightly curved walls 'I0 asbest seen in Fig. 3.

Wheel 62 is located on shaft 42 with the center line of its groove 68 precisely in the plane of the line of contact of the rolls I0 andl I2 sothat'a selvage of a web o f cloth engaged between the rolls will engageedgewise .in `the wheel groove when said selvaglemoves laterally outward of the rolls a predetermined amount. Also, the wheel `62 and its shaft 42 are located relative tothe desired' path of travel ofga selvage so that the selvage normally is within thel groove with the edge of the selvage spaced slightly from the bottom of the groove. Hence the selvagenormally is close enough to the groove vbottom so that only a relatively small outward departure of the selvage from its predetermined course will cause it to frictionally engage the bottom of the wheel groove 68 thereby to rotate the wheel and, through gear segment 58, to cause tilting of the rolls l0, I2 until the selvage moves out of contact with the wheel groove.

my improved selvage guider is extremely sensitive to departures of a selvage and responds substantially instantaneously to eifect a correction. The provision of ball-bearings at the journals of Iboth the swinging arm I4 and the wheel shaft 42 contributes to the sensitivity and eifectiveness and makes it practical and eliicient to ascomplish selvage control in response togedgewise engagement of the selvage with the wheel 62. i In order to ensurethat an outward moving -selvage will engage in groove 68 of wheel 62, I provide the two guide rods 12, I4 which are mounted as indicated generally at I6 on the frame into the wheel groove. The web engaging part of arm I4. 'Ihe forwardly projecting part of the 10 frame piece 44 has a rear bearing portion 48 and a forward bearing portion 58 betweenvwhich the It is an important feature of the invention that piece 44, and project inwardly below the rolls I0, l2 to well beyond the periphery of wheel 62.

of guide rod 14 is above the web engaging part of rod 12, and projects toward rod 12 a little beyond the plane of tne web, as best seen in Fig. 3. This arrangement and shape ofthe guide rods tensions the selvage somewhat to facilitate its entrance into the wheel groove 68.

Inasmuch as the surfaces of rolls I6, I2 preferally are of rubber, or the like, wear at the roll surfaces may require adjustment of the wheel 62 and of the guide rods 12, 14 so that they may be in proper relations to the vertical plane in which the cloth or other web leaves rolls I6, I2. Wheel 82 is adjustable along its shaft 42 by means of its plane where it would'be intersected by the 'pin to which the spring is -shown connected if that clamping nuts 64, 6B which engage the threaded portion 68 of the shaft. The guide rods 12, 14 are adjustable by reason of their seeurement to a block 13 which is fadjustably clamped to frame piece 44 by screws 16 passing through slot 11 in the frame piece.

The mechanism as herein illustrated has the center of gravity of the tiltable unit outward from its axis I6 so that, in Fig. 5, gravity tends to rotate the unit at the left counter-clockwise and the unit at the right clockwise about axis I6. This tendency is counteracted by a coil spring 18 which has one end secured as at 80 to the rollcarrying arm i4 and has its other end adjustably secured as at 92 to the fixed rod or bar 84 upstanding from the base I8. By adjusting the wing nut 86, the tension of spring 18 may be adjusted to attain anapproximate balancing of the tiltable unit with the rolls I0, I2 tilted at a desired angle. Ordinarily, in the mechanism herein disclosed, the tiltable unit initially will be adjuste'd so that spring 16 will maintain the unit with maximum tilt above the horizontal, such as at an angle of twenty-five degrees to the horizontal. Then, when a. web of cloth is engaged, this angle is reduced until the rolls Waver only slightly above or below the horizontal, and the selvage normally runs just out of contact with the bottom of groqve 68 in wheel 62.

It is a feature df the invention that spring 18 has its point 90 of securement roll-carrying arm I4 located in the plane of t e axes of the rolls I0, I2, and relatively close to the axis I8 lof rotation of the tiltable roll unit, so that the spring tension effect on the tiltable roll unit is increased only slightly as the unit moves from its position of balanced maximum tilt to its normal operating positions in which the rolls may have relatively slight tilt, or none at all, relative to the horizontal plane of the unit axis. It will be observed that the over-hung weight of the tiltable roll unit is such that gravity tends to rotate the unit in one plane about the axis I6 and also tends to rotate the unit in a vertical plane at right angles to the first'mentioned plane. Referring to Fig. 1, gravity not only tends to rotate the unit counter-clockwise about shaft I6 but tends to rotate the unit in direction to cause the upper end of shaft I6 to move toward the `eye and the lower end of shaft I6 to move away from the eye, thereby providing unequal distribution of the load on the bearings 60. An important feature of the invention is that the apparatus is designed so that the spring 18 applies torque to the tiltable unit which, in every position of the unit equalizes or nearly equalizes the load on.the bearings 60. Referring to Figs. 1

and 8, the preferable location for connection of' spring 18 to the tiltable unit would be in the midst of the rolls I0, I2 in a plane passing through the center of gravity of the unit and parallel with the roll axes at a location in said pin could be extended. However, the rolls Ill', I2 are in the way of such a preferred connection of spring 18 to the unit and the connection, for best results, should be made as close to roll I 9 as practicably possible, as shown in Fig. 8. Hence the unit tends to remain in a condition of approximate balance throughout its range of movement and is more sensitively responsive to selvage departures than any prior comparable mechanism of which- I am aware. Alsothe having of the securement 88 of the spring to the unit in the plane of the roll axes makes the mechanism more readily adaptable to different conditions which may have to be met in particular installations. For example, referring to Fig. 5, the cloth guiding mechanisms as illustrated are suitable for guidingoselvages of a web of cloth travelling vertically downward. If it is desired to have the web travel vertically upward, the same selvage guidera may be employed but each would be turned upside down and transposed so that each would be in the place of the other. Also the bar 84 of each guider, and its spring 18 would be shifted to extend above the reversed guiders, with the springs acting against the tendency of gravity to tilt the inner ends of the rolls ing of the connection lof each spring 18 to theframe in the plane of the axes of the rolls greatly facilitates and simplies the adaptation `of the guider mechanisms for working on webs travelling in different locations. When these connec- .tions are located to one side of the plane of the associated roll axes, as in prior` constructions. adaptation of a guider for working on an upwardtravelling web as above suggested has involved insertion of a link extension for each spring 18.

As herein represented. the spring 18 is a relatively strong coil spring. It should be underi stood, however, that the generally balanced condition of the tiltable roll unit may be attained with a light spring so long as itcan successfully counter-act the rotational eifect of gravity on the unit.

Referring now to the modified form of selvageengaging wheel shown in Figs. 6 and 7, this wheel may be generally similar in construction to the wheel. 62 of Figs. 1-4, but the groove walls are crimped or corrugated as indicated generally at 88, so that a selvage 90 engaging between the corrugated walls 92, 94 is caused to assume va rippled shape. As shown in detail in Fig. 7, the` selvage comes more and more into frictional engagement with the corrugated walls 92, 94 as it moves into the Wheel groove thereby to maintain the selvage taut and stabilized so that it more effectively and sensitively effects rotation of the wheel if and when it moves into frictional engagement with the bottom of the wheel groove.

Figs. 8 and 9 show a modification in which the selvage-engaging grooved wheel 62 is mounted on the tiltable roll unit and a gear segment 96 f is relatively fixed and has internal teeth 98 for meshing with the toothed portion 54 of the -wheel shaft 42. In this case, a frame piece 44 may have bearing portions 48, 59 for shaft '42 as in the previously described form but the frame piece 44 has secured thereto, or formed as an integral part thereof, the bracket by which the frame piece and its bearing portions 48, 50 may be rigidly mounted on the forward extension I4' of 5 arm I4. Also, Figs. 8. and 9 show a preferred attachment of the spring 18 to the tiltable unit in that the attachment is effected at 80' inward of the bearings for the tiltable unit. This has the important eiect of reducing substantially the friction at the bearings 60 due to the over-hung weight of the tiltable unit because the spring tends to counteract the overhung weight which otherwise tends strongly to tilt the bearing shaft in a vertical plane.

The arrangement of the selvage guiding rods 12, 'I4' in Figs. 8 and 9 is considered to-be a preferred arrangement because thereois assurance that a selvage travelling outward between the guide rods must enter the groove of wheel v62, whereas, with the rods spread as in Figs. 1 and 4, there may be a possibility that a selvage might escape the wheel groove and become engaged between a guide rod and a wheel flange.

It will be obvious from the foregoing that I have provided an improved selvage guider wherein a novel -control is attained by frictional engagement of a selvage with roll-tilting mechanism which may or may not continue in its initial position regardless of the positions of the web-engaging rolls and wherein a superior degree of sensitivity of control and general eciency are made possible, as compared with prior selvage guiders.

I claim as my invention: Y

l. In a web guiding machine, a pivoted unit having a pair of co-acting rolls for engaging opposite faces of a travelling web at a marginal region of the web, rotatable means on an axis transverse of the axes of said rolls and in the path of outward travel of said marginal region of said travelling web and adapted to be rotatedy by frictional engagement of said outward travelling web therewith, and means responsive to a rotation of said rotatable means for effecting a movement of said pivoted unit about its pivot.

2. In a web guiding machine, a pivoted unit having a pair of co-acting rolls for engaging opposite faces of a travelling web at a marginal region .of the web, means movable about an axis disposed generally transversely of the axes of the rolls and in the path of outward travel of an edge of said travelling web and adapted to be rotated by engagement of the web therewith, and means responsive to a rotation of said means and movable about an axis for swinging said unit about its pivot.

3. In a web guiding machine, a pivoted unit having a pair of co-acting rolls for engaging opposite faces of a travelling web ata marginal 60 region of the web, a shaft mounted generally\ transversely of the axes of the rolls, means fixed on said shaft in the path of outward travel of an edge of said travelling web and adapted to be moved about its axis thereby to rotate said shaft when frictionally engaged by` the web, leverage means, and means on said shaft co-acting with said leverage means to effect a rocking of said pivoted unit in response to rotation of said shaft.

fi. In a web guiding machine, a pivoted unit having a pair of co-acting rolls for engaging opposite faces of a travelling web at a marginal region of the web, means at a xed location blocking the path of outward travel of an edge of said travelling web and movable at said xed 75 8 location in response to engagement ofthe web therewith, and connections between said means and said pivoted unit for actuating said unit about its pivot in response to a movement of said means by the web.

5. A machine for guiding the selvage of a travelling web of cloth, comprising a pivoted unit including a pair of vcloth engaging rolls, a relatively xed support for said unit, means mounted on said support independently of said pivoted unit and standing rotatably at a xed location blocking the path of outward travel of a. selvage and rotatable in response to frictional engage-- ment of a said selvage therewith, and connections between said means and said pivoted unit whereby a rotation of said means by a said selvage eifects a movement of said unit about its pivot thereby to tilt said rolls, and said means continuing in its original position during tilting of the rolls.

6. A machine for guiding the selvage of a travelling web of cloth, comprising a pivoted unit including a pair of cloth engaging rolls, a.

relatively ilxed support for said unit, a shaft mounted rotatably generally transversely of the axes of the rolls, a wheel xed on said shaft and having a peripheral groove disposed in the path of outward travel of a selvage and adapted to receive a selvage edgewise therein,l anti-friction bearings for said shaft facilitating rotation of the shaft and wheel in response to frictional engagement of a travelling selvage with the walls of the peripheral groove of said wheel, Iand coacting means respectively on said relatively xed support and said pivoted unit and including means adapted to rotate in unison with said wheel for rocking said unit inlresponse to rotation of said wheel.

7. Cloth guiding mechanism comprising a pair of rolls for engaging between them a marginal region of a travelling web of cloth, a pivotally mounted frame supporting the rolls and movable about its pivot for tilting the rolls in general parallelism with the plane of travel of the web -between the rolls, pivoted means beyond the rolls therewith,` and connections between said pivoted means and said pivotally mounted frame for effecting a tilting of said rolls in response to a said movement of said pivoted means, and independently of drag of the web on said rolls.

8. Cloth guiding mechanism comprising a pivoted unit having a pair of rolls for engaging between them. a selvage region of a'travelling web of cloth, said unit being movable about its pivot to tilt saidrolls generally in parallelism with the plane of the web `travelling between them and being designed so that gravity tends to rotate the unit in one direction about its pivot, resilient means adjustably opposing said rotational tendency due to gravity, rotatable means fixed in position relative to said pivoted unit and disposed adjacent 'to the predetermined path of a travelling selvage blocking the way against any substantial lateral departure of the selvage from its said predetermined path and adapted to be rotated by frictional engagement therewith of a said selvage departing from said predetermined path, and mechanical connections for moving said pivoted unit about its pivot in response to a rotation of said rotatable means, thereby' to tilt said rolls in direction to restore said selvage to its predetermined path of travel. l

9. Cloth guiding mechanism comprising a pivoted unit having a pair of rolls for engaging between them a selvage region of a travelling web of cloth, said unit being movable about its pivot to tilt said rolls generally in parallelism with the plane of the web travelling between them and being designed so that gravity tends to rotate the unit in one direction about its pivot, resilient means adjustably opposing said rotational i tendency due to gravity, a shaft mounted rotatably with its extent generally transverse of the roll axes, means fixed on the shaft and disposed adjacent to the predetermined pathof a selvage and adapted to be engaged by a said selvage departing from said path thereby to cause rotation of said shaft, and inter-engaging means fixed respectively on said shaft and on said pivoted unit whereby a rotational movement of said shaft is transmitted to said unit to tilt said rolls.

10. Cloth guiding mechanism comprising a pivoted unit having a pair of rolls for engaging between them a selvage region of a travelling web of cloth, said unit being movable about its pivot to tilt said rolls generally in parallelism with the plane of the web travelling between them and' being designed so that gravity tends to rotate the unit in one direction about its pivot, resilient means adjustably opposing said'rotational tendency due to gravity, a shaft mounted rotatably with its extent generally transverse of the roll axes, a peripherally grooved wheel fixed on the shaft and located with the bottom of` its groove opposite and close to the'predetermined path of a selvage whereby a departure of the selvage from said path bringslit into frictional engagement with the bottom of said wheel groove thereby to' rotate the wheel, a gear on said shaft, and means on said pivoted unit` inter-engaged with said gear, whereby rotation of said shaft effects a tilting of said rolls.

11. A web guiding machine comprising a pivoted unit having a pair of co-acting rolls for engaging opposite faces of a travelling web at a marginal region of the web, means adjacent to the edge of said marginal region of the web blocking the path of outward travel of an edge of the web and responsive to frictional engagement of the web therewith for swinging said unit about its pivot, thereby to shift the axes of said rolls relative to a, predetermined plane, said pivoted unit tending to rotate in one direction about its pivot due to the force of gravity, and adjustable tension means acting on said pivoted unit in opposition to the force of gravity thereon and adjusted' to place said unit in a stateof approximate balance with the axes of said rolls in a predetermined plane.

l2. A web guiding machine comprising a pivoted unit having a frame and a pair of co-acting rolls supported by the frame for engaging opposite faces of a travelling web at a marginal region y pivot of said unit than to the plane of the outer ends of said rolls, said location of the connection.

of the spring to the unit frame being as close as practicably possible to the adjacent roll and thus acting web-engaging rolls, said unit tending to rotate in one plane about its pivot under the intluence of gravity and tending by gravity to rotate in a second plane at right angles to said first plane, e. coil spring acting on said unit in opposition to the influence of gravity thereon. said spring being designed and connected to the unit so that it approximately balances said tendency of the unit to rotate in said second plane, thereby tending to equalize the load on said spaced apart bearings, and means for adjusting the tension of said spring to place said unit in a condition of approximate balance when the axes of said rolls are in a predetermined plane.

14. Ina web-guiding machine having a pair oi' web-engaging rolls, a peripherally grooved wheel rotatably mounted for rotation about an axis transverse of the axes of said rolls and fixed relative to the predetermined path of a marginal region of a travelling web, said marginal region of the web normally travelling out of contact with the'walls of the groove of the wheel. and said wheel beingv rotatable in response to frictiona1 engagement of said marginal region of the web with a wall of the wheel groove.

. 15. In a web-guiding machine, a peripherally grooved wheel rotatably xed relative to the pre-v determined path of a marginal region of a. travelling web, the walls ofthe groove of the wheel being corrugated, and said marginal region of the web normally travelling out of contact with said corrugated walls of the wheel groove, means for guiding said marginal region of the web into the wheel groove whereby said marginal region `lof the web, upon outward departure from its predetermined path, engages the corrugated walls of the wheel groove whereby the selvage is conditioned for effective wheel-rotating frictional engagement in the bottom of the wheel groove, by being rendered-taut and stabilized as it travels into the groove.

16. In a web-guidingl machine having a pivoted unit with co-acting web-engaging rolls, said unit tending to rotate in one plane about its pivot under the influence of gravity and tending by gravity to rotate in a second plane at right angles to said first plane, a coil spring acting on said unit in opposition to the influence of gravity thereon, said spring being designed and connected to the unit so that it approximately balances said tendency of the unit to rotate in said second plane and means for adjusting the tension of said spring while the machine is in operation thereby to reduce the torque on said pivoted unit while themaximum torque during operation is eiective.` t

17. In a web-guiding machine having a pivoted unit f with co-acting `web-engaging rolls, means acting on said pivoted unit` and tending to maintain it in a condition of approximate balance with the axes of said rolls in a predetermined plane, a peripherally grooved wheel mounted rotatably on an axistransverse of the roll axes with its groove in the path of outward travel of an edge of a web engaged between said rolls, said edge of web being adapted to fric- 11 tance, and means responsive tov rotation of said wheel for eiecting a predetermined tilting of said pivoted unit thereby t0 modify the effect of said rolls on the web. f

18. In a webguiding machine having a pivoted unit with co-acting web-engaging rolls, means acting on said pivoted unit and tending to mainand tending also to rotate the unit in'a vertical plane at right angles to said pivotal axis, said means acting on the unit including a tension coil spring connected to the unit beyond said bearings in the direction of overhang of the unit and acting in opposition to said over-hung weight, said spring being designed and connected to the unit so thatit approximately balances the rotational tendency of the unit in said plane at right angles to said pivotal axis, thereby to reduce and equalize the load on said anti-friction bearings, and there being means for adjusting the tension oi' said spring to reduce the torque while the machine is in operation.

19. A web guiding machine comprising a pivoted unit having a pair of co-acting rolls for engaging opposite faces of a travelling web at a' marginal region of the webg pair of bearings for said unit spaced apart along the pivotal axis of the unit, said unit having its center of gravity located a substantial distance outward from said bearings in the general direction of extent of the I 35 Number pivotal axis of the unit and off-set substantially to one side of the plane of said pivotal axis of the A unit, whereby gravity tends to rotate the unit in one direction about its pivotal axis and tends also to. rotate the unit about a second axis at right angles to said pivotal axis of the unit, and adjustable tension means acting on said unit in opposition to gravity and adapted to counter-act the said tendency of gravity to rotate the unit ,about said second axis thereby to reduce and equalize the load 0n s'aid'pair of spaced apart bearings.

20. A 'web guiding machine `as in claim 19 wherein said adjustable tension means is a. coil spring having one end adjustably fixed in position and having its other end connected to said unit approximately in the plane of the axes of said rolls and between the parallel planes of the pivotal axis of the unit and the center of gravity of the unit, said spring reducing and equalizing the load on said bearings.

21. A web guiding machine as in claim 19 wherein said adjustable tension means is a coil spring having one end adjustably ixed in position and having its other end connected to said unit between the parallel planes of the unit axis and the center of gravity of the unit and also between parallel planes passing respectively through theicenter of gravity of the unit and through one of said bearings, the latter parallel f planes being at right angles to the first men- 4tioned parallel planes, said spring applying torque to the unit to reduce load on the bearings.

JOHN D. ROBERTSON.

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

UNITED STATES PATENTS and equalize the Name Date 1,835,438 Sichert Dec. 8, 1931 2,096,087 Coolidge Oct. 19, 1937 1,472,499 Smart et al Oct. 30, 1923 1,995,462 Tandel Mar. 26, 1935 2,118,375 Dungler May 24, 1938 1,185,173 Bolton May 30, 1916

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