Web-aligning apparatus

Abstract: Apparatus (10) for aligning an elongate web (12) with respect to a predetermined path of travel. The web (12) is supplied from a supply roll (20), and the apparatus (10) includes an axle assembly (36) adapted to hold the supply roll (20) for axial movement and rotation. A web guide (46, 48, 50) is provided for guiding the opposite edges (16, 18) of the outer web layer (24) of the supply roll (20) laterally with respect to the longitudinal direction of the web (12), with the axle assembly (36) affording translation of the supply roll (20) to accommodate telescoped or non-uniformly wound supply rolls (20), thereby to maintain alignment of the outer web layer (24) with respect to the predetermined path of travel.

Description: The invention relates generally to web-aligning apparatus, and more particularly to apparatus for aligning a web with respect to a predetermined path. Background of the Invention When processing webs, it is frequently necessary to align the webs being processed with respect to some predetermined path of travel. For example, it is usually desirable to maintain the edges of webs being laminated in alignment with one another, without reducing the typically high speeds of the web-laminating process. Improper alignment may lead to excessive waste of material, and low quality and possibly useless laminated web. Possible causes of improper alignment include, among other things, flexing of the web-laminating apparatus in operation, wandering of the web laterally with respect to its principal direction of motion along the rollers of the apparatus, and telescoping of the web on its web-supply roll, that is, the layers of the web in the roll being laterally or axially offset with respect to one another. Flexing of the apparatus has been reduced by over-designing the machinery to reduce or eliminate the flexing, although this increases the cost and weight of the machinery, and by supporting both ends of the rollers, although this makes loading the web-supply roll more difficult. U.S. Pat. No. 3,598,332 discloses, among other things, a web-supporting roller assembly including two circular flanges adjacent opposite ends of the roller, against which a loosely wound web on the roller can be tapped to align the edges of the wound web, thereby reducing or eliminating telescoping of the web on the roller. The flanges are centered on the axis of rotation of the roller, and rotate with the roller. It is believed that the assembly is unsuitable for aligning the edges of tightly wound web, the layers of which would resist being forced into edge alignment on the roller. U.S. Pat. No. 4,322,044 discloses paper alignment and loading apparatus utilizing a leaf spring mounted at one end of a drive roll and bearing against an edge of the wound paper to, among other things, laterally position the paper. U.S. Pat. No. 1,697,958 describes a device for applying strips of paper to roofing material. The device includes a shaft for carrying a roll of the paper, which is free to move axially along the shaft, and adjustable guide arms rigidly mounted on a U-shaped pipe that is free to move in response to sidewise movement of the roofing material. The guide arms are moved by the U-shaped pipe in order to maintain the roll of paper in position with respect to the roofing material. While that device realigns the roll of paper in response to movement of the roofing material, it would not maintain the material unwinding from a telescoped roll in proper alignment. U.S. Pat. No. 855,482 describes means for guiding a moving web or apron passing over a supporting roll. That means comprises among other things two normally-inactive detecting rolls in close proximity to the supporting roll. When the web engages either of the detecting rolls, the roll rotates and causes skewing of the supporting roll to return the web to its proper lateral position. U.S. Pat. No. 1,921,405 shows among other things a guide table having a pair of spaced and parallel guides fixed to the table, with web material passing between the parallel guides to bring the material into proper alignment. Web alignment has also been attempted by electronic tracking of the webs and shifting the webs in response to an electronic signal generated according to the position of the web. Electronically-controlled apparatus of various types are discussed in U.S. Pat. Nos. 3,244,340; 3,317,101; 4,068,789; 4,500,045; 4,527,069; 4,572,417; and 4,575,065. U.S. Pat. No. 3,784,076 discloses, among other things, a web guide roll having slats along its outer surface that translate in response to a signal to guide the web. Problems with such apparatus include the complexity and expense of the apparatus, and dependence on possibly unreliable electronic feedback to maintain the alignment of the webs. U.S. Patent No. 3,087,665 describes a mechanical roller guide, which is similar in some respects to the guide roll of U.S. Patent No. 3,784,076 in that the roller includes two or more tape contacting segments which translate axially relative to the roller to facilitate maintaining the tape in alignment. The mechanical roller guide includes two end flanges, against which the tape bears whenever the tape departs from proper alignment to return the tape to its proper position. The axial translation of the tape contacting segments purportedly reduces friction when the tape is realigned by the end flanges. GB-A-2,140,531 discloses a packaging machine including a roll comprising a mandrel for receiving the roll moved thereon from a free end thereof and an abutment member for limiting the movement of the roll on the mandrel and for aligning one end of the roll symmetrically with the mandrel axis. To allow simple and easy alignment of the roll with respect to the mandrel axis, gripping means are provided disposed at the mandrel at a distance from the abutment member displaced therefrom towards the free end of the mandrel. This document is used to form the preamble of the appended claims. Summary of the Invention According to the present invention there is provided a web handling apparatus comprising a frame, a cantilever axle mounted on the frame and having retaining means adapted to hold a supply roll for rotation about an axis to afford unwinding of a first web from the supply roll, characterised by:- the axle being mounted for movement in the axial direction to allow axial translation of the supply roll within a predetermined operating range; means, including an abutment member, for self-centered mounting of the supply roll on the retaining means with the center of the supply roll generally centered on the retaining means by pushing the supply roll onto the retaining means until additional axial motion of the supply roll is blocked by the abutment member, with the supply roll and the retaining means being free to translate axially within said predetermined operating range without the supply roll engaging the abutment member when the supply roll is mounted on the retaining means; laminating rollers mounted on the frame for laminating a first elongate web having a first-web-longitudinal direction to a second elongate web moving along a predetermined, generally constant path in a second-web-longitudinal direction, the first web having opposite edges extending longitudinally of the web and being supplied from the supply roll formed by the web being wound around an inner web layer and having an outer web layer, whereby said frame is adapted to be positioned in a predetermined orientation with respect to the second web; transferring means on the frame for transferring the first web to the laminating rollers; and an arm assembly pivotable on an axis generally parallel to the axis of the cantilever axle, the arm assembly having a free end, two guide rollers rotatably mounted on the arm assembly generally adjacent its free end, the guide rollers being constrained from axial motion such that the guide rollers are adapted to guide the outer web layer of the first web in predetermined relationship with the second-web-longitudinal direction as the guide rollers roll against the opposite edges of the outer web layer of the first web, with the axle affording translation of the supply roll to accommodate telescoped or non-uniformly wound supply rolls, thereby to maintain the first web unwinding from the supply roll in such orientation that the first web is transferred via the transferring means to the laminating rollers with the edges of the first web in a predetermined relationship with respect to the second web, and biasing means for biasing the free end of the arm assembly toward the axle to maintain the guide rollers in rolling engagement with the outer web layer of the supply roll, the biasing means including manually actuatable means for deactivating the biasing means to allow the arm assembly to be pivoted away from the axle, thereby facilitating replacement of the supply roll. Thus there is disclosed apparatus useful for aligning an elongate web with respect to a predetermined path of travel, even when the web is supplied on a telescoped or non-uniformly-wound roll; that is especially useful for aligning a first web with respect to a second web moving along a generally constant, predetermined path and for rapidly laminating the two elongate webs; that is designed to align the first web with respect to the second web to maintain the edges of the webs in a predetermined relationship, e.g., aligned, even when the first web is supplied on a telescoped supply roll; that is adapted for easy loading and unloading of the first web; and that is uncomplicated in design and reliable in use. Generally, the apparatus is adapted for aligning an elongate web having opposite edges extending longitudinally of the web. The web is supplied from a supply roll formed by the web being wound around an inner web layer and having an outer web layer. The apparatus comprises a frame, and rotatable-holding means on the frame adapted to hold the supply roll for rotation about an axis to afford unwinding of the web from the supply roll. The rotatable-holding means also affords axial movement of the supply roll. An alignment device is provided comprising an arm assembly mounted on the frame and pivotable on an axis generally parallel to the axis of the rotatable-holding means. The arm assembly has a free end, a web guide mounted on the arm assembly adjacent the free end thereof, and means for biasing the free end of the arm assembly toward the rotatable-holding means to maintain the web guide in engagement with the outer web layer of the supply roll. The arm-assembly-biasing means includes manually actuatable means for deactivating the arm-assembly-biasing means to allow the arm assembly to be pivoted away from the axle assembly, thereby facilitating replacement of the supply roll. The web guide is rigid in the direction parallel to the axis of the rotatable-holding means in order to guide the opposite edges of the outer web layer of the supply roll laterally with respect to the longitudinal direction of the web to maintain alignment of the outer web layer with respect to the predetermined path of travel. The rotatable-holding means permits translation of the supply roll to accommodate telescoped or non-uniformly wound supply rolls. In the disclosure, a cantilever axle assembly is mounted on the frame of the web-aligning apparatus. The axle assembly has a free end opposite the frame and a central longitudinal axis. The cantilever axle assembly comprises an inner elongate member mounted on the frame, and an outer cylindrical member mounted on the inner member adjacent the free end of the axle assembly. The inner member extends to the free end of the axle assembly coaxially with respect to the axle assembly, and the outer member has a longitudinally-extending internal bore or cavity extending coaxially with respect to the axle assembly and inner member from the free end toward the frame. The outer member also has supply-roll-retaining means adapted to hold the supply roll for rotation about an axis to afford unwinding of the web from the supply roll. Bearing means is provided for permitting the outer member to rotate relative to the central axis of the axle assembly and for permitting axial movement of the supply-roll-retaining means. The inner and outer members are adapted for maintaining the axis of the outer member, when loaded, in an orientation parallel to the position of the axis of the outer member when unloaded, thereby facilitating even tensioning of the web separating from the supply roll to reduce lateral wandering of the web. The apparatus is designed for laminating a first elongate web to a second elongate web moving along a predetermined, constant path. Thus, the frame is positioned in a predetermined orientation with respect to the second web, and web-laminating means is provided on the frame along the path of the second web for pressing the webs together to adhere the first web to the second web. Transferring means is also provided on the frame for transferring the first web to the web-laminating means. The alignment means maintains the first web unwinding from the supply roll in such orientation that the first web is transferred via the transferring means to the web-laminating means with the edges of the first web in a predetermined relationship with respect to the second web. Other features will be in part apparent and in part pointed out hereinafter. Brief Description of the Drawing The present invention will be further described with reference to the drawing wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawing, and wherein: Fig. 1 is a schematic view of apparatus of the invention; Fig. 2 is a top plan view of the apparatus of Fig. 1; Fig. 3 is an enlarged cross-sectional view substantially along line 2-2 of Fig. 1, illustrating a mechanism for compensating for changes in the weight of or tension acting on a web supply roll used in the apparatus; Fig. 4 is a further enlarged cross-sectional view similar to Fig. 3, showing the mechanism of Fig. 3 in its roll-loading position; and Fig. 5 is an enlarged cross-sectional view similar to Figs. 3 and 4, showing the mechanism compensating for load or tension. Description of a Preferred Embodiment Now referring to Fig. 1, apparatus of the invention is designated in its entirety by the reference numeral 10. The apparatus 10 is useful for aligning a first elongate web 12 with respect to a predetermined path of travel, and for laminating the first web 12 to a second elongate web 14. The first web 12 is elongate in a first-web-longitudinal direction, and the second web 14 is elongate in a second-web-longitudinal direction (horizontally leftwardly in Fig. 1). The second web 14 moves along a predetermined, generally constant horizontal path in the second-web-longitudinal direction (from right to left in Fig. 1). The first web 12 has opposite edges 16 and 18 extending longitudinally of the web, and is supplied from a first-web-supply roll 20 formed by the web being wound around an inner web layer 22 to an outer web layer 24. The first web 12 is preferably of the type having a layer 26 of pressure sensitive adhesive and a backing web or liner 28 covering the adhesive. The backing web 28 is adapted to be stripped away (at 30) from the first web 12 to expose the adhesive layer 26. Other types of adhesives, such as hot melt adhesives or adhesives that are applied to the web immediately before laminating, are also contemplated. The apparatus 10 is especially designed to be used as part of a process of fabricating automobile license plates from reflective sheeting (the first web), such as the reflective sheeting of the type sold under the trade designation "Reflecto-Lite" by the Minnesota Mining and Manufacturing Co. of St. Paul, Minnesota, and metal backing materials (the second web), such as aluminum or galvanized steel. The apparatus 10 is adapted to supply the laminated web 15 to other machines for further processing, such as cutting, stamping or sealing. The apparatus 10 may also be useful for laminating other types of webs and in other types of processes, and accordingly the scope of the invention should not be restricted to the specific types of webs or processes discussed herein. Generally, the apparatus 10 includes a frame 32 adapted to be positioned in a predetermined orientation with respect to the second web 14, and web-laminating means 34 (e.g., two opposed rollers 33 and 35) mounted on the frame along the path of the second web for pressing the webs 12 and 14 together to adhere the first web 12 to the second web. The upper web-laminating roller 33 may be a driven roller pulling the first web between the web-laminating rollers 33 and 35, and the lower web-laminating roller 35 may be an idler roller "nipping" or pressing the first and second webs 12 and 14 between the web-laminating rollers. Axle assembly 36, also described herein as rotatable-holding means 36, is provided on the frame 32 for rotatably holding the first-web-supply roll 20 to supply the first web 12 to the web-laminating means 34 at a longitudinal speed substantially equal to the longitudinal speed of the second web 14. The rotatable-holding means 36 and first-web-supply roll 20 are movable laterally (rightwardly and leftwardly in Figs. 2-5) relative to the first longitudinal direction, that is, they are free to translate along their common axis AX-3 of rotation. A brake 37 (Fig. 3) may be provided for stopping or resisting motion of the rotatable-holding means 36 to prevent premature unwinding or bunching up of the first web 12 on the first-web-supply roll 20 and to maintain tension in the first web 12. Transferring means 38 (e.g., wheel 72 and roller 74) is provided on the frame 32 for transferring the first web 12 from the first-web-supply roll 20 to the web-laminating means 34. An alignment device 40 is mounted on the frame 32 for aligning the first web 12 with respect to a predetermined path of travel. The alignment device 40 comprises first-web-guiding means (also 40) that is generally rigid in the direction generally parallel to the axis AX-3 of rotation of the rotatable-holding means 36 (e.g., right and left in Figs. 2-5). The first-web-guiding means 40 is adapted for guiding or positioning the opposite edges 16, 18 of the outer web layer 24 of the first-web-supply roll 20 laterally (e.g., leftwardly and rightwardly in Figs. 2-5) with respect to the first-web-longitudinal direction, with the rotatable-holding means 36 affording translation of the first-web-supply roll 20 to accommodate telescoped or non-uniformly wound supply rolls (see, e.g., Fig. 2). Thus the outer web layer 24 is maintained in alignment with respect to the predetermined path of travel. As shown in Figs. 1 and 2, the first-web-guiding means 40 comprises a pivotable arm assembly 42 mounted on the frame 32 and pivotable on axis AX-1. The arm assembly 42 is generally rigid in the direction generally parallel to the pivot axis AX-1 of the arm assembly and to the rotational axis AX-3 of the axle assembly 36. The arm assembly 42 has a free end 44 opposite the pivot axis AX-1. A web guide is mounted on the arm assembly 42 adjacent the free end 44. The web guide preferably comprises two guide rollers 46 and 48 rotatably supported on the arm assembly 42 by an axle 50 (Fig. 2) adjacent the free end 44 of the arm assembly. The guide rollers 46 and 48 are adapted to roll against the opposite edges 16 and 18 of the outer web layer 24 to position the outer web layer laterally relative to the second web 14. The guide rollers 46 and 48 preferably rotate around a common axis AX-2, e.g., the axle 50, that is substantially parallel to the rotational axis AX-3 of the rotatable-holding means 36. Each guide roller 46, 48 includes a circumferential shoulder 52, 54 extending generally radially outwardly from the roller for guiding one of the opposite edges 16, 18 of the outer web layer 24. Means 56 is preferably provided for biasing the free end 44 of the arm assembly 42 toward the rotatable-holding means 36. The biasing means 56 maintains the guide rollers 46 and 48 in rolling engagement with the outer web layer 24 of the first-web-supply roll 20 at a position designated 58 in Fig. 1 immediately before the web 12 separates from the roll as it is supplied to the web-laminating means 34. This arrangement is believed to reduce "bunching up" of the outer web layer 24 on the first-web-supply roll 20. The arm-assembly-biasing means 56 may comprise a manually actuatable air cylinder 60, one end of which is pivotably mounted on the frame 32, and a linkage 62 interconnecting the arm assembly 42 and the air cylinder such that, when the air cylinder is pressurized (Figs. 1 and 2), the arm assembly 42 is biased toward the rotatable-holding means 36. To facilitate replacement of the first-web-supply roll 20, manually actuatable means may be provided for deactivating or depressurizing the air cylinder 60. Such depressurizing means may include a directional control valve (not shown) connected to the air cylinder 60 via an air line 64. Deactivating the arm-assembly-biasing means 56 allows the arm assembly 42 to pivot away from the rotatable-holding means 36 sufficiently to permit placing a new first-web-supply roll 20 on the rotatable-holding means. Backing-stripping means 66 (Fig. 1) is provided for stripping the backing web 28 from the first web 12 before the first web is supplied to the web-laminating means 34, and a frame-mounted backing-web-storing or take-up roller 68 is provided for holding the backing web 28 after it is stripped from the first web 12. The backing-stripping means 66 includes a stripping bar 69 around which the backing web 28 is pulled to separate the backing web from the first web 12, and a frame-mounted idler roller 70 in rolling engagement with the backing web 28 and so positioned (e.g., substantially as shown in Fig. 1) that the backing web 28 is pulled from the first web 12 at a predetermined angle (e.g., approximately 90 degrees). Driving means is provided for driving the backing-web-storing roller 68 such that the backing web is pulled from the first web 12 around the stripping bar 69, along the idler roller 70, and wound around the backing-web-storing roller 68. The driving means may include a suitable driving motor (not shown) or a suitable linkage (e.g., a chain, driving belt, or the like) with the upper web-laminating roller 33 and/or the transferring means 38. The transferring means 38 (Fig. 1) comprises a pair of rollers or wheels, such as a frame-mounted, back-up idler roller 72 and a driven first-web-pulling wheel 74 rotatably mounted on the frame 32. The back-up roller 72 and first-web-pulling wheel 74 define a "nip point", at which the first web 12 is pulled by the first-web-pulling wheel 74 from the first-web-supply roll 20. The first-web-pulling wheel 74 is adapted to tension the first web 12 between the first-web-pulling wheel and the web-laminating means 34, and the backing-stripping means 66 is adapted to strip the backing web 28 from the first web 12 between the back-up roller 74 and the web-laminating means 34. The first-web-pulling wheel 74 may be coupled with the upper web-laminating roller 33 by a suitable linkage (e.g., gearing) to maintain the first-web-pulling wheel 74 at an appropriate rotational velocity relative to the driven laminating roller 33 for tensioning the first web 12 between the first-web-pulling wheel and the laminating rollers 33 and 35. As shown in Figs. 3-5, the rotatable-holding means 36 comprises a cantilever axle assembly (also 36) rotatably mounted on the frame 32 and having a central longitudinal axis AX-3 when unloaded. The cantilever axle assembly 36 comprises an inner elongate member 76 and an outer cylindrical member 78 having a rigidity substantially greater than the rigidity of the inner member. The inner member 76 is rotatably mounted on the frame 32, and extends generally coaxially outwardly (rightwardly in Figs. 3-5) with respect to the axle assembly 36 substantially to the free or outer end 80 of the axle assembly (i.e., the end opposite the frame). Bearing means is provided comprising low-friction bearings 82 rotatably supporting the inner member 76 on the frame 32 to permit the outer cylindrical member 78 to rotate relative to the the central axis AX-3 of the axle assembly. The inner and outer members 76 and 78 are substantially rigidly interconnected so that they rotate together on the bearings 82. The bearings 82 also permit axial movement (e.g., 2 in. (50mm) movement) of the inner member 76 relative to the frame 32 so that the axle assembly 36 moves with the first-web-supply roll 20 when the roll is pushed generally laterally by the first-web-guiding means 40. The outer cylindrical member 78 has a longitudinally-extending internal bore or cavity 84, and is mounted on the inner member 76 adjacent the free end 80 of the axle assembly 36. The outer member 78 extends substantially coaxially inwardly (leftwardly in Figs. 3-5) with respect to the axle assembly 36 and inner member 76 substantially from the free end 80 toward the frame 32. Supply-roll-retaining means 86 are mounted along the outer member 78 adjacent the inner end (left end in Figs. 3-5) of the outer member for holding the first-web-supply roll 20. For example, the supply-roll-retaining means 86 may comprise a chuck (also 86) having a plurality of spring-biased members (not shown) for releasably retaining the first-web-supply roll 20. Such a chuck is sold under the trade designation "Tilt-Lock" by the Central Machine Works Co. of Minneapolis, Minnesota. The inner and outer members 76 and 78 are adapted for maintaining the outer member in a generally horizontal orientation wherein the central longitudinal axis AX-4 of the outer member 78 is maintained in a generally parallel orientation with respect to the its unloaded orientation regardless of the actual load on the outer member (see Fig 5) so long as the actual load does not exceed the load for which the axle assembly 36 is designed. (As used herein, the "load" on the outer member 78 refers to the load due to tensioning of the first web 12 relative to the first-web-supply roll 20 and the weight of the first-web-supply roll.) As a result, the axis AX-4 of the outer member 78 is also maintained in a generally parallel orientation with respect to the axes of rotation of the back-up roller 72 and first-web-pulling wheel 74. This arrangement facilitates even longitudinal tensioning of the first web 12 laterally along the web between the first-web-supply roll 20 and the back-up roller 72. (That is, the tension of the first web 12 in the first-web-longitudinal direction is preferably maintained generally even or constant laterally along the web.) Maintaining such even tensioning of the first web 12 separating from the first-web-supply roll 20 is believed to improve tracking of the first web 12 and reduce lateral wandering of the web 12, and thereby to assist the alignment device 40 in maintaining the first web 12 in alignment with respect to its predetermined path of travel so that the first web 12 is laminated to the second web 14 with the edges of the webs maintained in a desired predetermined relationship (e.g., aligned). Abutment means 88 may be provided on the frame 32 for abutting the first-web-supply roll 20 during loading of the roll onto the axle assembly 36 to properly position the roll on the assembly. The abutment means 88 comprises an aluminum or steel abutment plate (also 88) mounted on the frame 32 and extending radially outwardly (upwardly and downwardly in Figs. 3-5) substantially from the axis AX-3 of the axle assembly 36 beyond the outer web layer 24 of an unused first-web-supply roll 20. The abutment means 88 cooperates with the bearings 82 to facilitate proper positioning of the first-web-supply roll 20. The bearings 82 permit axial movement of the axle assembly 36 between a roll-loading position (Fig. 4) and a range of operating positions (e.g., Figs. 3 and 5 show the axle assembly 36 in one of the operating positions). When the axle assembly 36 is in its roll-loading position (Fig. 4), the supply-roll-retaining means 86 is spaced from the abutment plate 88 by a bearing housing 90 such that the first-web-supply roll 20 is centered over the supply-roll-retaining means 86 when the roll 20 abuts the plate 88. Thus the first-web-supply roll 20 may be properly centered over the supply-roll-retaining means 86 merely by pushing the roll onto the supply-roll-retaining means as far as the roll will go, that is, until it abuts plate 88. The range of operating positions of the axle assembly 36 is defined as those positions wherein the supply-roll-retaining means 86 is spaced sufficiently from the abutment plate 88 to hold a first-web-supply roll 20 centered on the supply-roll-retaining means (as discussed above) spaced sufficiently from the abutment plate to prevent rubbing of the roll 20 against the plate 88 during operation of the apparatus 10. An annular rubber bumper 92 may be provided on the inner elongate member 76 between the bearing housing 90, on one side, and the outer member 78 and chuck 86, on the other side. The bumper 92 reduces the noise that would otherwise be caused the outer member 78 and chuck 86 hitting the bearing housing 90 when the axle assembly 36 is pushed to its roll-loading position. In operation, the first web 12 is pulled from the first-web-supply roll 20 at 58 by the first-web-pulling wheel 74. The first web 12 travels around the first-web-pulling wheel 74 after reversing direction around the back-up roller 72. The first web 12 is then pulled from the first-web-pulling wheel 74 by the upper web-laminating wheel 33, and is pressed between the web-laminating wheels 33 and 35 with the second web 14 to laminate the webs. Between the first-web-pulling wheel 74 and web-laminating wheels 35, the backing web 28 is stripped from the adhesive side 26 of the first web by the stripping bar 69, and pulled along the idler roller 70 onto the take-up roller 68. The guide rollers 46 and 48 roll against the outer web layer 24 to maintain the outer web layer 24 and the first web 12 in proper orientation relative to the desired path of travel of the first web 12, the axle assembly 36 translating axially to compensate for any telescoping or non-uniform winding of the first-web-supply roll 20. Thus the first web 12 is supplied to the back-up roller 72 and first-web-pulling wheel 74, and then to the web-laminating wheels 35, with the edges 16, 18 of the first web 12 in alignment with the edges of the second web 14.

Claims: A web handling apparatus comprising a frame (32), a cantilever axle (36) mounted on the frame (32) and having retaining means (86) adapted to hold a supply roll (20) for rotation about an axis (AX-3) to afford unwinding of a first web (12) from the supply roll (20), characterised by:- the axle (36) being mounted for movement in the axial direction to allow axial translation of the supply roll within a predetermined operating range; means (76, 78, 82, 88), including an abutment member (88), for self-centered mounting of the supply roll (20) on the retaining means with the center of the supply roll generally centered on the retaining means (86) by pushing the supply roll (20) onto the retaining means (86) until additional axial motion of the supply roll (20) is blocked by the abutment member (88), with the supply roll and the retaining means being free to translate axially within said predetermined operating range without the supply roll engaging the abutment member when the supply roll is mounted on the retaining means; laminating rollers (33, 35) mounted on the frame (32) for laminating a first elongate web (12) having a first-web-longitudinal direction to a second elongate web (14) moving along a predetermined, generally constant path in a second-web-longitudinal direction, the first web having opposite edges extending longitudinally of the web and being supplied from the supply roll formed by the web being wound around an inner web layer and having an outer web layer, whereby said frame (32) is adapted to be positioned in a predetermined orientation with respect to the second web (14); transferring means (38) on the frame (32) for transferring the first web (12) to the laminating rollers (33, 35); and an arm assembly (42) pivotable on an axis (AX-1) generally parallel to the axis (AX-3) of the cantilever axle (36), the arm assembly having a free end (44), two guide rollers (46, 48) rotatably mounted on the arm assembly generally adjacent its free end (44), the guide rollers being constrained from axial motion such that the guide rollers (46, 48) are adapted to guide the outer web layer of the first web (12) in predetermined relationship with the second-web-longitudinal direction as the guide rollers roll against the opposite edges of the outer web layer of the first web, with the axle (36) affording translation of the supply roll (20) to accommodate telescoped or non-uniformly wound supply rolls, thereby to maintain the first web (12) unwinding from the supply roll (20) in such orientation that the first web (12) is transferred via the transferring means (38) to the laminating rollers (33, 35) with the edges of the first web in a predetermined relationship with respect to the second web (14), and biasing means (56, 60, 62, 64) for biasing the free end of the arm assembly (42) toward the axle (36) to maintain the guide rollers (46, 48) in rolling engagement with the outer web layer of the supply roll (20), the biasing means including manually actuatable means (64) for deactivating the biasing means to allow the arm assembly to be pivoted away from the axle (36), thereby facilitating replacement of the supply roll (20). Apparatus according to claim 1 wherein the means (76, 78, 82, 88) for self-centered mounting of the supply roll (20) on the retaining means (86) comprises: the abutment member (88) which is on the frame (32) for abutting the supply roll during loading of the supply roll onto the retaining means to position the supply roll on the cantilever axle; and means (82) for allowing axial movement of the cantilever axle (36) between a loading position, in which the axle is constrained from additional movement in the axial direction generally toward the abutment member (88) and the retaining means is spaced from the abutment member such that the supply roll is substantially centered over the retaining means when the supply roll abuts the abutment member, and a range of operating positions, in which the retaining means (86) is spaced sufficiently from the abutment member (88) to hold a supply roll (20) centered on the retaining means (86) with the supply roll (20) spaced from the abutment member (88). Apparatus according to claim 2 wherein the cantilever axle assembly comprises: an inner elongate member (76) mounted on the frame (32) and extending substantially to the free end of the axle (36) generally coaxially with respect to the axle; an outer cylindrical member (78) having a longitudinally-extending internal bore or cavity mounted on the inner member adjacent the free end of the axle (36) and extending substantially coaxially with respect to the axle and inner member (76) substantially from the free end toward the frame (32), the retaining means (86) being mounted on the outer cylindrical member; and bearing means (82) permitting the outer cylindrical member (78) to rotate relative to the central axis of the axle (36); the inner (76) and outer (78) members being adapted for maintaining the axis of the outer member, when loaded, in an orientation generally parallel to the position of the axis of the outer member when unloaded, thereby facilitating even tensioning of the first web (12) separating from the supply roll to reduce lateral wandering of the web. Apparatus according to claim 3 wherein the bearing means (82) comprises generally low friction bearings (82) rotatably supporting the inner member (76) on the frame (32), the inner (76) and the outer (78) members being substantially rigidly interconnected so that they rotate together, the bearings (82) permitting axial movement of the inner members (76) relative to the frame (32) so that the axle assembly moves with the supply roll (20) when the supply roll (20) is pushed generally laterally by the guide rollers (46, 48). Apparatus according to claim 4 wherein the outer cylindrical member (78) extends from an outer end adjacent the free end of the axle (36) toward the frame (32) to an inner end, the retaining means (86) being positioned along the outer member (78) adjacent the inner end of the outer member, the retaining means (86) comprising a chuck having a plurality of spring-biased members for releasably retaining the supply roll. Apparatus according to claim 5 wherein the guide rollers (46, 48) are mounted on the arm assembly (42) for rotation about an axis that is generally parallel to the axis of the cantilever axle (36), each guide roller including a circumferential shoulder extending generally radially outwardly from the roller for guiding one of the opposite edges of the outer web layer of the supply roll, and the guide rollers (46, 48) being biased against the outer web layer (24) of the supply roll (20) at a position immediately before the first web (12) separates from the roll (20). Apparatus according to claim 2 wherein the biasing means (56, 60, 62) comprises a manually actuatable air cylinder (60) and a linkage (62) interconnecting the arm assembly (42) and the air cylinder (60) such that, when the air cylinder (60) is pressurized, the arm assembly (42) is biased toward the cantilever axle (36), the manually actuatable means for deactivating the biasing means (64) including a valve for depressurizing the air cylinder (60) to allow the arm assembly (42) to be pivoted away from the cantilever axle (36), thereby facilitating replacement of the supply roll (20). Apparatus according to claim 2 wherein the first web (12) is of the type having a layer of pressure sensitive adhesive (26) and a backing web (28) covering the adhesive and being adapted to be stripped away from the first web (12) to expose the adhesive layer, the apparatus further comprising stripping means (66, 69, 70) mounted on the frame (32) for stripping the backing web (28) from the first web (12) before the first web (12) is supplied to the laminating rollers (33, 35), and a storing roller (68) for holding the backing web (28) after it is stripped from the first web (12), the stripping means (66, 69, 70) comprising a stripping bar (69) around which the backing web (28) is separated from the first web (12), an idler roller (70) in rolling engagement with the backing web (28) so positioned that the backing web (28) is pulled from the first web (12) at a predetermined angle, and driving means for driving the storing roller (68) such that the backing web (28) is pulled around the stripping bar (69), along the idler roller (70), and wound around the storing roller (68). Apparatus according to claim 8 wherein the transferring means comprises a pulling wheel (74) for pulling the first web (12) from the supply roll (20), and a back-up roller (72) around which the first web runs (12) before being pulled around the pulling wheel (74), the pulling wheel (74) and back-up roller (72) defining a nip point where the first web is nipped between the pulling wheel (74) and back-up roller (72), the pulling wheel (74) being adapted to tension the first web between the pulling wheel (74) and the laminating rollers (33, 35), and the stripping means (66, 69, 70) being adapted to strip the backing web from the first web between the pulling wheel and the laminating rollers (33, 35), the transferring means further comprising linkage means for controlling the relative rotational velocity of at least one of the laminating rollers and the pulling wheel.

Inventors: ANDERSON CONRAD V MINNESOTA MI, ANDERSON, CONRAD V.,MINNESOTA MINING & MANUFACT., Anderson, Conrad V.,Minnesota Mining &amp; Manufact.
Applicants: MINNESOTA MINING & MFG, MINNESOTA MINING AND MANUFACTURING COMPANY
Application year: 1989
Main classification: B65H23
IPC codes: B65H16, B65H39, B65H23