US3069056A

US3069056A - Web guiding and edge stretching means

Info

Publication number: US3069056A
Application number: US23878A
Authority: US
Inventors: Howard R Richards; Alexander V Alexeff
Original assignee: Industrial Ovens Inc
Current assignee: Industrial Ovens Inc
Priority date: 1960-04-13
Filing date: 1960-04-13
Publication date: 1962-12-18
Anticipated expiration: 1979-12-18

Description

Dem 18, 1962 H. R. RICHARDS ETAL 3,069,056

WEB GUIDING AND EDGE STRETCHING MEANS Filed April 13, 1960 5 Sheets-Sheet l IN VEN TORS ALEXANDER V. ALEXEF F ATTORNEYS HOWARD R. RICHARDS 8 1962 H. R. RICHARDS ETAL 3,069,056

GUIDING AND EDGE STRETCHING MEANS Filed April 13, 1960 5 Sheets-Sheet 2 INVENTORS HOWARD R. RICHARDS 8 7 By ALEXANDER V ALEXEFF ATTORNEYS Dec. 18, 1962 H. R. RICHARDS ETAL 3,069,056

WEB GUIDING AND EDGE STRETCHING MEANS Filed April 13, 1960 5 Sheets-Sheet 3 FIG. /0

INVENTORS HOWARD R. RICHARDS a BY ALEXANDER VALEXEFF ATTORNEYS Dec. 18, 1962 H. R. RICHARDS ETAL WEB GUIDING AND EDGE STRETCHING MEANS Filed April 13, 1960 5 Sheets-Sheet 4 ll 140 1 I37 133 INVENTORS HOWARD R. RICHARDS 8 BY ALEXANDER V. ALEXEFF ATTORNEYS Dec. 18, 1962 H. R. RICHARDS ETAL WEB GUIDING AND EDGE STRETCHING MEANS Filed April 15, 1960 5 Sheets-Sheet 5 INVENTORS HOWARD R. RICHARDS 8 ALEXANDER ALEXEFF @i xmyjw ATTORNEYS United States Patent Ofiice,

3,069,056 Pa'te'nted Dec. 18, 1962 3,069,056 WEB GUIDING AND EDGE STRETCHING MEANS Howard R. Richards, Lakewood, and Alexander V. Alexeif, Cleveland, Ohio, assignors to Industrial Ovens, Incorporated, Cleveland, Ohio, a corporation of Ohio Filed Apr. 13, 1960, Ser. No. 23,878

' .5 Claims. (Cl. 226-22) This invention relates to web guiding means and particularly to guide rolls for maintaining edge alignment andcentering of traveling webs.

Several proposals have been made for the provision of guide rolls designed to compensate for web misalignment and to simultaneously obtain quick correction of misalignment by means having an infinite capacity for transverse shifting of the web (e.g., US. Patent 2,786,-

675) or by means having a limited capacity of transverse shifting of the Web, such limited transverse shifting being accompanied by compensatory angular adjustment of the guide roll means (e.g., US; Patents 2,722,415; 2,797,091).

There have also been provided bowed rolls including rolls of an automatically adjusting type adapted to respond to control means to thereby accomplish guidance as well as stretching of the web. One type of such bowed roll web guiding and stretching means employs independentadjusting means at each e nd of the bowed roll (e.g., US. Patent 2,823,443): to accomplish independent guidance of .each web edge in response to an edge location sensing means, a number of which are known in the art. Adjustment of the amount of bow obviously affects adjustment of the angular relationships between the roll and web. However such bowed roll does not accomplish quick-correct action since the roll cannot shift transversely in two directions at once or otherwise effect quick correction. Hence such bowed roll depends essentially on variation of its guiding action to effect correction without any supplemental quick-correct action.

. The present invention contemplates the accomplishment of independent edge alignment of each edge of a web in such a manner that quick-correct action is also achieved or at least achievable.

. In one important aspect, the present invention contemplates the accomplishment of independent edge alignment of each edge of a web in such a manner that bodily transverse shifting of the web occurs incident to compensatory angular adjustment of the guiding means.

A feature of the present invention is the accomplishment of correction in such a manner that transverse stretching of portions of the Web width may be accomplished at precisely the zones where shrinkage normally occurs in web processing lines due to cumulative effects of inevitable small roll misalignnients of the various rolls around which the web passes.

Another object of the invention is to accomplish web centering by compensatory angular adjustments or eifective angular adjustments of the web guiding means and by concurrent transverse shifting of the web, it being within the contemplation of the invention that portions of the web which are at opposite locations in the web width may be simultaneously transversely shifted in opposite directions from each other if such action is called for at any instant.

Another object of the invention is to provide web guiding apparatus having the above features but which in certain aspects of the invention may be bodily replaced as a unit-on a web processing line for maintenance and servicing purposes without disassembly of the guiding apparatus and without the necessity of emptying or partially emptying the processing line of web material contained therein.

,Reference above is made to effective angular adjustments. A particularly important aspect of the invention contemplates alternate and progressive association and disassociation of relatively angularly positioned guide roll means with a passing web to accomplish effective angular adjustment irrespective of whether the axis of the roll is itself moved through an angle, although such angular movement of the roll axis may be desirably included even in this aspect of the invention in many instances. v

The feature of association and disassociation between the web and roll is not critical to all phases of the invention.

In another important aspect, the invention contemplates the accomplishment of independent edge alignment of each edge of a web by roll means which has a correcting action which is a function of the difference between web speed and the tangential velocities of the roll means, such tangential velocities being variable independently of web speed. s I

Another object of the invention is the provision of improved edge sensing and control means for governing the corrective motion of the web guide roll means.

The objects and advantages of the invention will be more clearly understood from the following description of specific embodiments emphasizing the invention.

In the drawings:

FIGURE 1 is a fragmentary side elevation of a portion of a Web processing line illustrating apparatus embodying the invention. FIGURE 1 is an elevation taken across the width of the processing line..

FIGURE 2 is a fragmentary view taken fromthe plane of line 22 in FIGURE 1.

FIGURE 3 is a fragmentary view taken from the plane of line 3-3 in FIGURE 1.

FIGURE 4 is a view similar to FIGURE 2 illustrating variations in certain of the features thereof.

FIGURE 5 is a fragmentary view similar to a portion of FIGURE 1 and on a somewhat enlarged scale showingan alternative example of the invention- FIGURE 6 is a view taken from the plane of line 66 in FIGURE 5.

FIGURE 7 is an elevational view of a portion of the web processing line illustrating another form of apparatus embodying the invention.

FIGURE 8 is a plan view of the apparatus seen in FIGURE 7.

FIGURE 9 is a view taken from line 9--9 in FIG- URE 8. Y

FIGURE 10 is a schematic illustration of edge sensing means and associated control means for use in web guiding applications according to one aspect of the invention.

FIGURE 11 is an elevational view of a portion of the web processing line illustrating still another form of ap; paratus embodying the invention.

FIGURE 12 is a view taken from line 12-12 in URE 11.

FIGURE 13 is an elevational view of a portion of the web processing line illustrating still another form of apparatus embodying the invention.

FIGURE 14 is a View taken from line 1414 in FIG- URE 13. i

Illustrated in FIGURE 1 are guide roll means comprising first and second rolls 10 and 11 shown in FIG- URES -3 adapted to guide a passing flexible web 12,

such as tire fabric material or other web material.

The roll 10 is rotatably mounted in a pair of

end bearings

15 and 16 which are carried by swinging

links

17 and 18, respectively. The link 17 is tied to actuating rods or straps 19 coupled to a threaded shaft 20, which is mounted in suitable bearing means and which is powered through a slip connection by an air motor 21. The ar-' rangernent is such that when the air motor 21-is actuated to move the structure from the extreme rightmost position illustrated in FIGURE 2, the pivoting motion of the

links

17 and 18 is such as to raise the left end of the roll and lower the right end of the roll as the roll is seen in FIGURE 2. Such motion accomplishes engagement of the roll 10 with the passing web 12. The further the motion occurs to the left from the position illustrated in FIGURE 2, the deeper such engagement becomes, such engagement being at all times deeper at the edge of the web which is first contacted by the roll 10 and progressively less deep at progressively greater distances from such edge due to the angular inclination of the roll 10 into the web 12.

It will be understood that in the extreme rightmost position which is the position illustrated in FIGURES 1 and 2, the roll 10 may be completely out of contact with the passing web 12.

Provided in the vicinity of the guiding apparatus and at the web edge which is associated with the roll 10 is an edge senser unit operatively associated with the roll 10 through control means (including the motor 21) as schematically illustrated in FIGURE 10. Many components of such control means may be positioned within the housing 40 illustrated in FIGURE 1. The edge senser unit may comprise a tube 41 having a slot 53 and supplied with low pressure air through a spring-loaded regulator 42' which reduces the pressure of the air supply line 45 to say about p.s.i. The static pressure at the tube 41 is imposed on the input side of a pressure multiplier 50 through line 43. Operating air is supplied to the pressure multiplier through line 44 from the air supply line 45 at a suitable pressure of say 30 p.s.i. effected by the spring-loaded pressure regulator 46. The output line 47 varies in pressure in a well known manner according to the input pressure signal through line 43 to thereby actuate the diaphragm 48 of a diphragm-actuated springloaded valve 49 adapted to port air from the air supply line 45 and spring-loaded pressure regulator to the air motor 21 through lines 51 and 52 for forward, zero and reverse rotation thereof according to the position of the edge of the web 12 over the slot 53 in the tube 41. In some aspects of the present invention the details of the above-described edge senser and web control system are immaterial and such sensing unit and control means may comprise mechanical, pneumatic, hydraulic, or electronic means or combinations thereof, a number of variants of such senser and control means being known to the art. The above-described control means has been described in detail to assure fullest disclosure of the invention and also because, as an edge control system, it is unusually reliable and effective, particularly in view of its relative simplicity and low cost. A particular feature as contemplated by this aspect of the present invention is the generation of a control pressure signal by variable venting of a slotted chamber effected by shifting of a passing web over the chamber slot. With this arrangement the shifting of the web directly and simply varies static pressure responsively to web position even though very low pressures of only several p.s.i. are applied to the exhausted air.

As shown in FIGURE 1, the roll in this embodiment of the invention does not transversely extend in an exact perpendicular relationship with the direction of travel of the web but rather extends angularly with respect thereto. Although the particular angle is not critical, an angle of approximately seven degrees is desirable in many instances where the angularity does not itself change in shifting of the roll, in the manner to be described below. The angle of seven degrees or other equivalent angles are in such a direction that the end of the roll 10 which initially contacts the web 12 in the correction of shifting movement of the roll 10 from the neutral or initial position shown in FIGURE 2 is the upstream end of the roll 10 with reference to the direction of web movement. Thus, the web 12 illustrated in FIGURE 1 would be moving in the downward direction, as indicated by an arrow in FIGURE 1.

The roll 11 is located in closely associated spaced relationship with the roll 10 along the path of travel of the web 12. The mounting and control for the roll 11 is identical to that of the roll 10 with the exception that the movement from neutral position occurs in the opposite direction so that the roll 11 initially contacts the opposite edge of the passing web 12 and engages such web in a progressively deeper relationship in its movement from neutral position in a manner corresponding to the action of the roll 10. It will be understood that in the extreme leftmost position illustrated in FIGURE 1, the roll 11 may be completely out of contact with the passing web 12.

It will thus be seen that each of the rolls 10 and 11 is mounted to shift bodily back and forth across the passing web 12 and for simultaneous movement back and forth between limiting end conditions of a relatively large and a relatively diminished degree of engagement with its associated lateral portion of the web width (such diminished degree being no engagement whatsoever in this particular example), with such engagement being at all times deepest at the associated edge of the web and progressively less deep at progressively greater distances from the associated edge.

It is within the contemplation of one broader aspect of the invention that the axes of the rolls 10 and 11 remain in the same angular position throughout the shifting of the rolls. This would be the case, for example, were the

links

17 and 18 parallel to each other and were the equivalent means which mount the roll 11 also parallel to each other, with the distance between the pivot points of the link 18 somewhat increased to incline the roll 10 toward the left edge of the fabric 12 as these parts are viewed in FIGURE 2. It will be understood, of course, that the roll 11 would be identically arranged in the opposite manner to incline it initially in an opposite sense. Such an arrangement of the mounting of the roll 10 is illustrated in FIGURE 4, where identical elements are numbered with identical reference numerals and wherein similar elements are numbered with similar reference numerals with the addition of the letter a. Shifting of the rolls 10a and 1111 (not shown) involves only translation (along both axial and transverse vectors) of the guide rolls but nevertheless provides for simultaneous movement back and forth into deeper and less deep engagement of each roll with its associated lateral portion of the width of the passing web, and such engagement continues to be at all times deepest at the associated edge of the web and progressively less deep at progressively greater distances from such associated edge.

In some instances, it is desirable to vary the angularity of the attitude of the rolls illustrated in FIGURE 1; that is, the angularity which makes one end of each roll more upstream than the other end. This may be accomplished by supplementing the pivot pin connection between the bearing block 16 and the link 18 shown in FIGURES 1 and 2 by a ball-and-socket joint 30 or equivalent, as illustrated in FIGURES 5 and 6, and by mounting the link 18 (designated in FIGURES 5 and 6 as 181;) for pivoting movement about axes 23b which are not parallel to the corresponding axes on the link 17b (link 17b is not shown but is identical to link 17 in FIGURES 1 and 2). This is in contrast to the corresponding axes 23 in FIGURE 1 which are parallel to the corresponding axes on the link 17. The result is that as the roll 10 moves from the position shown in FIGURE 5 to the left, the upstream-downstream aspect of the type shown in FIGURES l and 5 progressively increases in angularity in a direction which effects compensatory angular adjustment of the roll in the correct direction. Again, it will be understood that the roll 11 may be provided with the identical arrangement except in the opposite sense. It should be understood that in all the above cases, interaction between the rolls 10 and 11 (or 10a and 11a or 10b and 11b) and the passing web 12 is such that during engagement of each of the rolls with the web there is a tendency of that roll to stretch the web laterally from its center toward the edge associated with the particular roll, 'such associated edge being understood to be the edge initially contacted by the roll.

It is a particular advantage of the present invention that the guiding action accomplished by the rolls is accompanied not only by the quick-correct action effected by the bodily shifting of the rolls but that accompanying web stretching occurs at the zones where it is most needed, i.e., toward the edges of the web.

It will be understood that in the above embodiments of the invention, the guide rolls may extend across a longitudinally central portion of the reach of the passing Web 12. In the apparatus illustrated in FIGURES 7-9, the guide roll means itself constitutes idler roll means for suspending the web in entrained relation and for defining the end of one reach and the beginning of another. In these figures, there is illustrated a pair of guide rolls 60 and 61 in entrained relationship with a web 62. The ends of the guide roll 61 are received in bearing blocks 63 and 64 pivotally suspended from fixed structure by means of

links

65 and 66, respectively. The shaft of the roll 61 is tied for axial translation with a nut 81 threaded to a screw shaft 67 which through a suitable flexible coupling 68 is rotatable by an air motor 69. The roll 61 is adapted to move only to the right from the position shown in FIGURES 7 and 8. The arrangement of the links associated with the roll 60 is identicalwith those described in connection with the roll 61 with the excep tion that the end stop positions and the screw-shaft threads of the actuating linkage for its suspending links are such as to make the position of the roll 60 shown in FIGURE 8 the extreme leftmost position of this roll. In this regard, the associated threaded portions of the screw shaft 77 is illustrated in an oppositely disposed relationship with its coacting nut 80 than is the threaded portion of the screw shaft 67 with its coacting nut 81. The

rolls

60 and 61 are associated with first and second senser means 70 and 71, respectively, for sensing their respective associated web edges and with control means responsive to the respective sensing means for controlling movement of the

rolls

60 and 61, respectively, away from their neutral positions shonw in FIGURES 7 and 8, the roll 60 being controlled to move progressively'to the left from its neutral position and the roll 61 controlled to move progressively to the right from its neutral position in response to the degree of misalignment of the associated web edge indicated by the sensing means.

Such sensing means may be identical to that described above and illustrated in FIGURE 10, or it may comprise other mechanical, pneumatic, hydraulic, or electronic means which in the guide-apparatus aspects of the in vention are equivalent to the apparatus of FIGURE 10, although generally more expensive and more complex than the apparatus of FIGURE 10. If the sensing means is of the type shown in FIGURE 10, the

lines

72 and 73 from the senser 71 lead to the air motor 69 while the

lines

74 and 75 from the senser 70 lead to the air motor 76 associated with the roll 60.

It is to be noted that in the apparatus of FIGURES 7-9 as in the case of the apparatus of FIGURES 1-6, there is accomplished independent guidance of each web edge by rolls mounted for bodily shifting back and forth across the width of the passing web and for simultaneous back and forth movement between limiting end conditions of a relatively large and a relatively diminished degree of engagement with their associated lateral portions of the Web width. Again as in the apparatus of FIGURES 1-6, such engagement is at all times deepest at the associated edge of the web and progressively less deep at progressively greater distances from the associated edge. In this connection it will be understood that the roll 60 is associated with the leftmost lateral portion of the Web 62 and that the roll 61 is associated with the rightmost lateralportion of the web 62 as that web is viewed in FIGURES 7 and 8. In the example 6 of FIGURES 7-9, the guide rolls are a all times in en gagement with the passing web in entrained relationship therewith.

In the apparatus illustrated in FIGURES 11 and 12, there are again provided first and second roll means for independently stretching transversely outwardly the opposed lateral po-rtions of a Web width. In the apparatus shown in these figures, the first and second roll means each comprises first and second helix means mounted for rolling contact with the passing web. Thus in FIGURE 11 is shown a roll means comprising asplit roll including the

halves

101 and 102. The roll halves 101 and 102 are adapted to rotate independently of each other. Associated with the roll half Ellis a helix means 103 comprising spiral-wound wire welded to the periphery of the roll. The terminal ends of the Wire are suitably faired into the roll to prevent snagging Alternatively, the helix means 103 may comprise threadlike grooves cut in the core.

Associated with the roll 102 is a similar helix means 104.

In the apparatus illustratedin FIGURES 11 and 12, a roll 106 is provided in paired association with the roll 10%, the

rolls

100 and 106 being rotatably mounted between pivoting frame members 107. The'pivoting frame members 107 are pivotally supported on 'cross members 108 and may be held in adjusted position by adjustable-length linkages tied between the upper ends of the pivoting frame member and fixed frame members 110. Such adjustable-length linkages may comprise hydraulic cylinder linkages 111.

In the apparatus illustrated in FIGURES'II and 12, the roll halves 101 and 102 are powered by the roll 106 which itself is driven by the passing web 115. The web moves in a downward direction as illustrated in the figures. The drive of the roll half 101 is accomplished through the end shaft 117 of the roll 106 and then through a variable speed mechanism 118 and then through the shaft 119 of the roll half 101. The drive ratio of the variable speed mechanism 118 is controlled by the angular position of the control arm 120. The control-arm 120 is pivoted to a nut 121 mounted on a threaded shaft 122 which is rotatable in two directions by an air motor 124. The roll half 101 is associated with first senser means 126 for sensing the associated edge of the web 115. Control means is provided re sponsive to the sensing means 126 for controlling the setting of the arm 120 and therefore the drive ratio through the variable speed drive 118, the control being in such a direction that the tangential velocity of the roll half 101 is increased over that of the roll 106 as the associated edge of the web 115 moves inwardly toward the center of the roll assembly, and conversely the amount of excess speed of the. roll half 101 over the speed of the roll 106 is diminished as the associated edge of the web 115 moves laterally outwardly.

The drive of the roll half 102 is accomplished through the end shaft 137 of the roll 106 and then through a variable speed mechanism 138 and then through the shaft 139 of the roll half 102. The drive ratio of the variable speed mechanism 138 is controlled by the angular position of the control arm 140. The control arm 140 is pivoted to a nut 141 mounted on a threaded shaft 142 which is rotatable in two directions by an air motor 144. The roll half 102 is associated with second senser means 146 for sensing the associated edge of the web 115. Control means is provided responsive to the sensing means 146 for controlling the setting of the arm 140 and therefore the drive ratio through the variable speed drive 138, the control being in such a direction that the tangential velocity of the roll half 102 is increased over that of the roll 106 as the associated edge of the web 115 moves inwardly toward the aoeaose the roll 106 is diminished as the associated edge of the web 115 moves laterally outwardly.

The sensing means 126 and 146 may be identical to the sensing means previously described and illustrated in FIGURE 10 or, again, it may comprise other mechanical, pneumatic, hydraulic or electronic means which in the guide-apparatus aspects of the invention are equivalent to the apparatus of FIGURE 10. If the sensing means 126 and 146 are of the type shown in FIGURE 10, the

lines

127 and 128 lead to the air motor 124, and the

lines

147 and 148 lead to the air motor 144.

The apparatus as described immediately above effects correcting action by raising the speed of rotation of the helix means above web speed. However in some applications, it may be practical to effect correcting action by reversing the hand of the helix means and slowing the helix means below web speed. This may be accomplished by the illustrated apparatus by arranging the variable speed drives 118 and 138 for a speed-reducing relationship from the input to the output rolls rather than a speed-multiplying relationshi therebetween. Alternatively, it may be accomplished in certain applications without any power drive from the roll 106 to the roll halves 101 and 102 but rather by control of an application of progressively greater braking force on the

shafts

119 and 139 by brake shoes (not shown), the progressive application and release of which are controlled by the

air motors

124 and 144.

Expansion or contraction of the linkage 111 by actuation of the hydraulic cylinders forming a part thereof will set the assembly carried between the members 107 at various angles to thereby adjust the angle of thrust of the passing web with respect to the roll assembly. This determines the degree of sensitivity of fabric control accomplished by the apparatus, This degree of sensitivity may be pre-set and may involve the choice of different optimum angles for different web materials, or the angle may be adjusted automatically as a function of web speed or as a function of other desired parameters.

In all the above mentioned possibilities in connection with the apparatus of FIGURES 11 and 12, it will be understood that the control means associated with the first and second helix means 103 and 104 in all cases comprise means for varying the difference between the velocity of the web (the tangential velocity of the roll 106) and the tangential velocity of the helix means 103 from zero to progressively greater values (which may be algebraically positive or negative) in correspondence to progressive variation from zero of the distance between (1) the desired reference position of the web edge associated with the helix means 103 and (2) the actual position of such web edge. It will also be clear that in all cases described above in connection with FIGURES 11 and 12, similar control means is provided in similar relation for the helix means 104.

In the apparatus illustrated in FIGURES 13 and 14, there are provided

rolls

151 and 152. The roll 151 has associated therewith first helix means 153 and the roll 152 has associated therewith second helix means 154.

The

rolls

151 and 152 are rotatably mounted between pivoting frame members 155. The pivoting frame members 155 are pivotally supported on cross members 156 and may be held in adjustable position by adjustablelength linkages tied between the upper ends of the pivoting frame members and fixed frame members 157. Such adjustable-length linkages may comprise hydraulic cylinders 158.

In the apparatus illustrated in FIGURES 13 and 14 the roll 151 and the helix means 153 associated therewith are powered by a motor 161 the speed of which may vary withoverall line speed of the processing line through which the web 160 is passing and the speed of which remains constant for any given line speed. Therefore, assuming that the web 160 is driven through the processing line at a constant speed, the speed of the motor 161 remains constant.

The roll 151 is driven by the electric motor 161 through a variable speed drive 162 and then through the shaft 163 of the roll 151. The drive ratio of the variable speed mechanism 162 is controlled by the angular position of the control arm 164. The control arm 164 is pivoted to a nut 165 mounted on a threaded shaft 166 which is rotatable in two directions by an air motor 167. The roll 151 is associated with first sensing means 168 for sensing the associated edge of the web 160. Control means is provided responsive to the sensing means 168 for controlling the setting of the arm 164 and therefore the drive ratio through the variable speed drive 162, the control being in such direction that the tangential velocity of the helix means 153 is increased over line velocity of the web 160 as the associated edge of the web 160 moves inwardly toward the center of the web and conversely the amount of excess speed of the helix means 153 over the line speed of the web 160 is diminished as the associated edge of the web 160 moves laterally outwardly.

The roll 152 and the helix means 154 associated therewith are powered by a motor 181, the speed of which may vary with overall line speed of the processing line through which the web 160 is passing and the speed of which remains constant for any given line speed. Therefore, assuming that the web 160 is driven through the processing line at a constant speed, the speed of the motor 181 remains constant.

The roll 152 is driven by the electric motor 181 through a variable speed drive 182 and then through the shaft 183 of the roll 152. The drive ratio of the variable speed mechanism 182 is controlled by the angular position of the control arm 184. The control arms 184 is pivoted to a nut 185 mounted on a threaded shaft 186 which is rotatable in two directions by an air motor 187. The roll 152 is associated with second senser means 188 for sensing the associated edge of the web 160. Control means is provided responsive to the sensing means 188 for controlling the setting of the arm 184 and therefore the drive ratio through the variable speed drive 182, the control being in such direction that the tangential velocity of the helix means 154 is increased over line velocity of the web 160 as the associated edge of the web 169 moves inwardly toward the center of the web and conversely the amount of excess speed of the helix means 154 over the line speed of the web 160 is diminished as the associated edge of the web 160 moves laterally outwardly.

Again, the sensing means 168 and 188 may be identical to the sensing means previously described and illustrated in FIGURE 10 or they may comprise other mechanical, pneumatic, hydraulic or electronic means which in the guide-apparatus aspects of the invention are equivalent to the apparatus of FIGURE 10. If the sensing means 168 and 188 are of the type shown in FIGURE 10, the

lines

169 and 170 lead to the air motor 167 and the

lines

189 and 190 lead to the air motor 187.

The apparatus shown in FIGURES l3 and 14 may, similarly to the apparatus shown in FIGURES 11 and 12, effect correcting action by reversing the hand of the helix means and slowing the helix means below web speed. This would involve for example the re-arrangement of the variable speed drives 162 and 182 for speedreducing relationship from the

drive motors

161 and 181 to the

rolls

151 and 152 respectively.

Expansion or contraction of the linkages 158 in the apparatus shown in FIGURES 13 and 14 adjusts the assembly carried between the members 155 at various angles to thereby adjust the angle of thrust of the passing web with respect to the roll assembly. Again, as in the case of the previously described apparatus shown in FIG- URES 11 and 12, the adjustment of such angle determines the degree of sensitivity of fabric control accomplished by the apparatus, but in the case of the apparatus shown in FIGURES 13 and 14, as one edge increases in sensitivity of adjustment, the other decreases. The neutral position as to sensitivity is that illustrated in the drawings.

In all the above-mentioned possibility in connection with the apparatus of FIGURES 13 and 14, it will be understood that the control means associated with the first and second helix means 153 and 154 in all cases comprises means for varying the difference between the velocity of the web and the tangential velocity of the helix means 153 from zero to progressively greater values (which may be algebraically positive or negative) in correspondence to progressive variation from Zero of the distance between (1) the desired reference position of the web edge associated with the helix means 153 and (2) the actual position of such web edge. It will also be clear that in all cases described above in connection with FIGURES 13 and 14, similar control means is provided in similar relationship for the helix means 154.

The variable speed means 118, 13%, 162, and 182 described above in connection with the embodiments of FIGURES 11 and 13 may comp-rise any conventional gear ratio changing mechanism, such as frictional variable speed ratio drives, belt and sprocket variable speed ratio drives, expansible pulley belt and sprocket type speed ratio changing mechanisms or planetary gearing arrangements with continuously variable speed output, all of which are well known types of machine elements and mechanisms.

This application is a continuation-in-part of our copending application Serial No. 859,951 filed December 16, 1959, now abandoned.

The above description of the invention should make it apparent that many details of the apparatus embodying the invention may be varied without departing from the teaching of the invention. Accordingly, the scope of the invention is not to be limited to precise details of the specifically described embodiments but is to be defined by the following claims.

What is claimed is:

1. Web guiding apparatus comprising guide roll means for contacting a passing Web, said guide roll means including first and second roll means for independently simultaneously stretching transversely outwardly respectively the first and second opposed lateral portions of the web width, first and second means for sensing the positions of the web edges associated with said first and second portions of the web width, respectively, and control means responsive to each of said sensing means for controlling movement of said first and second roll means, respectively, to thereby responsively control stretching and edge positioning of respectively said first and second opposed lateral portions of the web width, said first and second roll means being both located along a longitudinal extent of said web which is short as compared to the width of the web.

2. Apparatus as in claim 1 in which said first and second roll means each comprises a roll mounted for bodily shifting back and forth across the passing web and simultaneous movement back and forth between limiting end conditions of a relatively large and a relatively diminished degree of en agement with its associated lateral portion of the web width with said engagement being at all times deepest at the associated edge of the web and progressively less deep at progressively greater distances from said associated edge.

3. Apparatus as in claim 2 in which said rolls are mounted for movement of their axes through a degree of angular displacement incident to said back and forth movements thereof.

4. Apparatus as in claim 1 where said first and second roll means are mounted to move entirely out of contact with said web to thereby establish said limiting end condition of relatively diminished degree of engagement at no engagement whatsoever.

5. Apparatus as in claim 1, said first and second roll means each comprising respectively first and second helix means mounted for rolling contact with the passing web, said control means comprising first means for varying the diiference between the velocity of said web and the tangential velocity of said first helix means from zero to progressively greater values in correspondence to progressive variance from zero of the distance between (1) the desired reference position of the web edge associated with said first helix means and (2) the actual position of said last named web edge, said control means also comprising second means for varying the difference between the velocity of said web and the tangential velocity of said second helix means from zero to progressively greater values in correspondence to progressive variance from zero of the distance between (1) the desired reference position of the web edge associated with said second helix means and (2) the actual position of said last named web edge.

References Cited in the file of this patent UNITED STATES PATENTS 2,353,653 Croft et a1 July 18, 1944 2,387,036 Morse Oct. 16, 1945 2,476,070 Solliday July 12, 1949 2,491,636 Amos Dec. 20, 1949 2,539,131 Gundersen Ian. 23, 1951 2,666,598 Robinette Jan. 19, 1954 2,726,858 Cherigie Dec. 13, 1955 2,779,591 Huck Jan. 29, 1957 2,797,091 Fife June 25, 1957 2,806,694 Penman Sept. 17, 1957 2,807,465 Newell Sept. 24, 1957 2,941,572 Densen et al. June 21, 1960