WO2001053156A1

WO2001053156A1 - Application of adhesive-backed elements to moving web or articles

Info

Publication number: WO2001053156A1
Application number: PCT/US2000/017184
Authority: WO
Inventors: Douglas A. Swenson
Original assignee: 3M Innovative Properties Company
Priority date: 2000-01-21
Filing date: 2000-06-22
Publication date: 2001-07-26
Also published as: AU2000258831A1; AR027264A1

Abstract

An apparatus and method for application of adhesive-backed elements to a moving web or articles makes use of a rotary cutting cylinder to cut elements of desired shape from an input web, and a vacuum drum to receive the elements and deliver them to an output web, such as a web of diaper stock. The vacuum drum is servo controlled so that the vacuum drum accelerates to deliver of adhesive-backed elements to the output web, and decelerates to receive adhesive-backed elements from the rotary cutting cylinder. In particular, rotation of the vacuum drum is controlled to substantially match the surface speed of the rotary cutting cylinder to receive the elements, and substantially match the surface speed of the output web to deliver the elements. In this manner, the elements can cut to a desired shape and placed on the output web with precision and increased throughput.

Description

APPLICATION OF ADHESIVE-BACKED ELEMENTS TO MOVING WEB OR ARTICLES

TECHNICAL FIELD The present invention relates to an apparatus and method for application of adhesive-backed elements to a moving web.

BACKGROUND

Various machines have been designed for the application of elements such as labels, inserts, and tapes to a moving web or a series of moving articles. For example, some machines are designed for high-speed application of labels to magazines, catalogs, and other printed forms. Other machines apply labels to boxes, bottles, cans, and the like. In some cases, machines are designed to apply the elements to a moving web that is later converted, e.g., by cutting, stamping, or slitting, to form a finished product or a component in a finished product.

One process that ordinarily involves a moving web is the application of closure tabs to diaper stock. The tabs may be formed from adhesive tape or hook-and-loop fastener material. The tabs form part of the closure mechanism for diapers formed with the diaper stock, and therefore must be placed with precision. At the same time, the machine must be carefully controlled to receive the tape tabs for application. The tape tabs generally are cut as rectangular strips from an input web. The tabs are applied to a vacuum drum that, in turn, carries them to an output web. The movement of the vacuum drum is synchronized relative to the output web to ensure proper placement of the tabs.

SUMMARY

The present invention is directed to an apparatus and method for application of adhesive-backed elements to a moving web or articles. The apparatus and method facilitate an in-line process for production of elements with a desired shape along with precise placement of such elements on a moving web or article. In some embodiments, the apparatus and method can be configured for application of closure tabs to a moving web of diaper stock. Advantageously, the apparatus and method enable the cutting of tabs with unique shapes that may involve rounded corners and other desired features without sacrificing precision in positioning of the tabs on the moving web. In one embodiment, the present invention provides an apparatus for application of adhesive-backed elements, the apparatus comprising a first web transport mechanism that transports a first web of adhesive backed material, a rotary cutting cylinder disposed adjacent the first web, the rotary cutting cylinder including cutting elements, a first drive mechanism that rotates the rotary cutting cylinder such that the cutting elements cut and remove adhesive-backed elements from the first web, a second web transport mechanism that transports a second web, a vacuum drum disposed between the rotary cutting cylinder and the second web, a second drive mechanism that rotates the vacuum drum to remove the adhesive-backed elements from the rotary cutting cylinder and deliver the adhesive- backed elements to the second web, and a controller that controls the second drive mechanism such that the vacuum drum rotates at different surface speeds for the removal of the adhesive-backed elements from the rotary cutting cylinder and the delivery of the adhesive-backed elements to the second web.

In another embodiment, the present invention provides an apparatus for application of adhesive-backed elements, the apparatus comprising a transfer element disposed between a supply of adhesive-backed elements and an article for receipt of one or more of the adhesive-backed elements, a drive mechanism that drives the transfer element to accept the adhesive-backed elements from the supply and deliver the adhesive-backed elements to the article, and a controller that controls the drive mechanism such that the transfer element moves at different speeds for the acceptance of the adhesive-backed elements from the supply and the delivery of the adhesive-backed elements to the article. In a further embodiment, the present invention provides a method for application of adhesive-backed elements, the method comprising transporting a first web of adhesive backed material, rotating a rotary cutting cylinder adjacent the first web, the rotary cutting cylinder including cutting elements, whereby the cutting elements cut and remove adhesive-backed elements from the first web, transporting a second web, rotating a vacuum drum between the rotary cutting cylinder and the second web to remove the adhesive-backed elements from the rotary cutting cylinder and deliver the adhesive- backed elements to the second web, and controlling the rotation of the vacuum drum such that the vacuum drum rotates at different surface speeds for the removal of the adhesive- backed elements from the rotary cutting cylinder and the delivery of the adhesive-backed elements to the second web. In an added embodiment, the present invention provides a method for application of adhesive-backed elements, the method comprising moving a transfer element between a supply of adhesive-backed elements and an article for receipt of one or more of the adhesive-backed elements, whereby the transfer element accepts the adhesive-backed elements from the supply and delivers the adhesive-backed elements to the article, and controlling the movement of the transfer element such that the transfer element moves at different speeds for the acceptance of the adhesive-backed elements from the supply and the delivery of the adhesive-backed elements to the article.

In another embodiment, the present invention provides a method for application of adhesive-backed elements, the method comprising moving a transfer element between a supply of adhesive-backed elements and an article for receipt of one or more of the adhesive-backed elements, whereby the transfer element accepts the adhesive-backed elements from the supply and delivers the adhesive-backed elements to the article, and decelerating the movement of the transfer element for the acceptance of the adhesive- backed elements from the supply, and accelerating the movement of the transfer element for delivery of the adhesive-backed elements to the article.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end view of an apparatus for application of adhesive-backed elements to a moving web; FIG. 2 is a side view of an apparatus as shown in FIG. 1 ;

FIG. 3 is a cross-sectional side view of a vacuum drum;

FIG. 4 is another cross-sectional side view of a vacuum drum;

FIG. 5 is an end view of the vacuum drum of FIGS. 3 and 4;

FIG. 6 is an end view of a vacuum manifold for use with a vacuum drum as shown in FIGS. 3-5;

FIG. 7 is a cross-sectional side view of a rotary cutting cylinder;

FIG. 8 is an end view of the rotary cutting cylinder of FIG. 7; FIG. 9 is a diagram of an adhesive-backed web for cutting adhesive-backed elements;

FIG. 10 is a diagram illustrating placement of tape tabs on a diaper stock web; and

FIG. 11 is a functional block diagram illustrating a control system for controlling an apparatus as shown in FIG. 1.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION FIG. 1 is an end view of an apparatus 10 for application of adhesive-backed elements 12 to a moving output web 14, in accordance with an embodiment of the present invention. Apparatus 10 can be used to perform a method in accordance with an embodiment of the present invention. For diaper applications, elements 12 may be closure tabs formed by adhesive tape or hook-and-look fastening material. In this case, web 14 may take the form of a web of diaper stock. For other applications, elements 12 may take the form of labels for application to printed media, boxes, bottles, cans, and the like. An embodiment of apparatus 10 configured for diaper applications will be described herein for purposes of illustration.

As shown in FIG. 1, apparatus 10 may include an anvil roller 16 with a shaft 18 and a rotary cutting cylinder 22 having cutting elements 24 and a shaft 26. Rotary cutting cylinder 22 can be disposed adjacent an input web 20 of adhesive-backed material and opposite anvil roller 16. Anvil roller 16 and rotary cutting cylinder 22 are rotatable about shafts 18, 26, respectively. Anvil roller 16 and rotary cutting cylinder 22 may form a nip

21 that contacts input web 20 on opposite sides. Anvil roller 16 and rotary cutting cylinder 22 act as a web transport mechanism, producing frictional force with input web

20 at nip 21 that operates to transport the input web between a supply roll and a takeup roll in the direction indicated by arrow 23 as the anvil roller and rotary cutting cylinder rotate. As an alternative, the takeup roll or other intermediate nip drives may act as a web transport for web 20. Cutting elements 24 are distributed about the outer surface of rotary cutting cylinder 22. A first drive mechanism (not shown in FIG. 1) rotates rotary cutting cylinder

22 about shaft 26 in a direction indicated by arrow 25 such that cutting elements 24 cut and remove adhesive-backed elements 12 from input web 20. Cutting elements 24 can be shaped as desired to remove uniquely shaped elements 12 from input web 20. In particular, cutting elements 24 can be shaped to cut rectangular tabs with rounded corners, leaving behind a scrim portion of web 20 that is carried away from nip 21 to a takeup roll with the remainder of the web. As will be described, the first drive mechanism may take the form of a servo-controlled electric motor coupled to transmit rotational force to shaft 26 of rotary cutting cylinder 22, either directly or via one or more gears or belts.

A second web transport mechanism transports output web 14. A vacuum drum 28 is disposed between rotary cutting cylinder 22 and web 14. A second drive mechanism (not shown in FIG. 1) rotates vacuum drum 28 in a direction indicated by arrow 29 about a shaft 30 to remove adhesive-backed elements 12 from rotary cutting cylinder 22 and deliver the adhesive-backed elements to web 14. Vacuum drum 28 forms a nip 27 with rotary cutting cylinder 22. Vacuum recesses 32 are oriented on the outer surface 34 of vacuum drum 28 to receive adhesive-backed elements 12 from cutting elements 24 on rotary cutting cylinder 22. In this manner, vacuum drum 28 acts as a transfer element between a supply of adhesive-backed elements 12 and an article for receipt of the adhesive-backed elements, e.g., web 14. The second drive mechanism may take the form of a servo-controlled electric motor coupled to transmit rotational force to shaft 30 of vacuum drum 28, either directly or via one or more gears or belts. A controller (not shown in FIG. 1) controls the second drive mechanism such that vacuum drum 28 rotates at different surface speeds for synchronized removal of adhesive-backed elements 12 from rotary cutting cylinder 22 and delivery of the adhesive-backed elements to web 14.

A buffing roll 36 supports web 14 against vacuum drum 28, and forms a nip 37. As shown in FIG. 1, output web 14 passes through nip 37 and moves in a direction indicated by arrow 39 toward a takeup roll (not shown). Buffing roll 36 may be actively driven about shaft 38, directly or via one or more gears or belt, in a direction indicated by arrow 41. As an alternative, buffing roll 36 may be passively driven by frictional interaction with web 14 in nip 37. In either case, buffing roll 36 supports web 14 for delivery of adhesive-backed elements 12 from vacuum roll 28. Again, web 14 may take the form of diaper stock. FIG. 2 is a side view of apparatus 10. In the example of FIG. 2, bearing blocks, frames, and other mounting hardware are omitted for ease of illustration. As shown in FIG. 2, anvil roll 16 is mounted about drive shaft 18, which that is coupled to servo motor 42 via motor shaft 44 and coupling collar 46. A gear reduction box may be coupled between motor 42 and drive shaft 40. Rotary cutting cylinder 22 may include two or more cylinder sections 22a, 22b, each of which is axially displaced from one another along the length of shaft 26. Cylinder sections 22a, 22b include a series of cutting elements 24a, 24b disposed at different positions around the circumferences of each section. Drive shaft 26 is coupled to servo motor 50 via motor shaft 52 and coupling collar 54. A gear reduction box also may be coupled between motor 50 and drive shaft 26. The two sections

22a, 22b may be arranged to accommodate two different input webs 14, each of which permits the cutting of adhesive-backed elements 12. The input webs can be transported side-by-side, and in alignment with sections 22a, 22b, to cut pairs of elements 12 for affixation to opposite sides of diaper stock formed by web 14. In particular, each pair of adhesive-backed elements 12 provides the right and left closure tabs for a respective diaper.

Like rotary cutting cylinder 22, vacuum drum 28 may include two cylinder sections 28a, 28b that are axially displaced from one another along the length of shaft 30. Each vacuum cylinder section 28a, 28b includes a number of vacuum recesses 32a, 32b distributed about the circumference of the respective section. Shaft 30 is coupled to servo motor 58 via motor shaft 60 and coupling collar 62. Again, a gear reduction box may be coupled between motor 58 and drive shaft 30. Sections 28a, 28b are arranged in alignment with cutting elements 24a, 24b, respectively, of rotary cutting cylinder sections 22a, 22b to receive pairs of adhesive-backed elements 12. Buffing roll 36 is mounted about drive shaft 38, which can be coupled to a servo motor 66 via a belt 72 mounted about pulley 70 and pulley 68. Pulley 68 is coupled to motor shaft 74, whereas pulley 72 is coupled to shaft 38. Alternatively, drive shaft 38 could be coaxially coupled to motor shaft 74. A gear reduction box also may be coupled between motor 66 and drive shaft 38.

In the example of FIG. 2, anvil roll 16, rotary cutting cylinder 22, vacuum drum 28, and buffing roll 36 are all actively driven. Servo control of drive motor 58 associated with vacuum drum 28, in particular, enables precise cutting and placement of adhesive- backed elements 12 on web 14. As will be described, drive motor 58 is controlled such that vacuum drum 28 rotates at different surface speeds for the removal of the adhesive- backed elements 12 from rotary cutting cylinder 22 and the delivery of the adhesive- backed elements to web 14. In particular, vacuum drum 28 rotates at the same surface speed as rotary cutting cylinder 22 for removal of adhesive-backed elements 12, but is momentarily accelerated to the same surface speed as web 14 when the adhesive-backed elements are placed on output web 14. In operation, each of motors 42, 50, 58, and 66 can be realized by a commercially available servo motor. An exemplary servo motor is commercially available as model number 1326AS-B330H-21 from Allen-Bradley of Milwaukee, Wisconsin. The surface speed of web 14 can be several times faster than that of rotary cutting cylinder 22. Generally, as the speed mismatch between web 14 and rotary cutting cylinder 22 increases, the number of applications of adhesive-backed elements 12 per unit time decreases. With servo control as contemplated herein, however, vacuum drum 28 can be selectively accelerated and decelerated, acting as an intermediary between rotary cutting cylinder 22 and web 14. The timing for acceleration and deceleration will depend, of course, on the relative rotational speeds, diameters, and resulting surface speeds of the rotary cutting cylinder 22 and vacuum drum 28. When one of cutting elements 24a, 24b of rotary cutting cylinder 22 approaches nip 27 between the rotary cutting cylinder and vacuum drum 28, the vacuum drum is decelerated to match the surface speed of the rotary cutting cylinder and thereby facilitate exchange of one of adhesive-backed elements 12.

As one of vacuum recesses 32 of vacuum drum 28 approaches the nip 37 with web 14, the vacuum drum is quickly accelerated to match the greater surface speed of web 14 and facilitate precise placement of one of adhesive-backed elements 12 on the web. Thus, motor 58 is controlled in an alternating fashion to accelerate and decelerate vacuum drum 28.

Although a close match in surface speed is highly desirable, the surface speed of vacuum drum 28 need not be identical to that of rotary cutting cylinder 22 or web 14. Instead, for satisfactory precision, it ordinarily will be sufficient that vacuum drum 28 rotate at a surface speed that is within approximately ten percent of the surface speed of rotary cutting cylinder 22 and web 14. In any event, the surface speed of vacuum drum 28 ordinarily will be greater for the delivery of the adhesive-backed elements 12 to output web 14 than for the removal of the adhesive-backed elements from rotary cutting cylinder 22. Therefore, the magnitude of the difference in surface speed may be higher between vacuum drum 28 and output web 14 than between the vacuum drum and rotary cutting cylinder 22. In some embodiments, acceleration and deceleration of rotary cutting cylinder 22 and vacuum drum 28 can be coordinated. In particular, when one of cutting elements 24a, 24b of rotary cutting cylinder 22 approaches nip 27 between the rotary cutting cylinder and vacuum drum 28, the vacuum drum can be decelerated while the rotary cutting cylinder is accelerated, such that they converge toward a match in surface speed. Thus, motor 50, like motor 58, can be controlled in an alternating fashion to accelerate and decelerate rotary cutting cylinder 22. FIG. 3 is a side view of vacuum drum 28 in further detail. FIG. 4 is another side view of vacuum drum 28, with the drum rotated relative to FIG. 3 to make vacuum recesses 32a, 32b more visible. As shown in FIGS. 3 and 4, each vacuum recess 32a, 32b can be coupled to vacuum drum sections 28a, 28b using set screws 76, 78 and 80, 82, respectively. Each vacuum recess 32a, 32b defines an edge 84, 86, respectively, that proscribe recessed portions 85, 87 for receipt of adhesive-backed elements 12. Vacuum recesses 32a, 32b can be distributed about the outer circumference of each vacuum drum section 28a, 28b, as indicated by reference numerals 32aι, 32a , 32b], 32b₂. Vacuum ports 88, 90 can be provided in vacuum recesses 32a, 32b, respectively, to retain adhesive- backed elements 12 after they have been cut from input web 20 by rotary cutting cylinder 22 and delivered to vacuum drum 28. Vacuum ports 88, 90 are coupled to internal vacuum channels (not shown) drilled in vacuum drum sections 28a, 28b which, in turn, are coupled to a source of vacuum pressure.

FIG. 5 is a cross-sectional end view of vacuum drum section 28a of FIGS. 3 and 4. As shown in FIG. 5, vacuum drum section 28a may incorporate three or more vacuum recesses 32aι, 32a₂, 32a that rotate into position to receive adhesive-backed elements 12 from rotary cutting cylinder 22. Each vacuum recess 32aι, 32a , 32a₃ is raised from the surface of vacuum drum section 28a, and defines an area for receipt of adhesive-backed element 12 from rotary cutting cylinder 22. Each adhesive-backed element 12 that is received from rotary cutting cylinder 22 is carried by the respective vacuum recess 32aι , 32a₂, 32a₃ to a position for delivery of the element to output web 14. Vacuum channels 89, 91 communicate with ports 88, 90, respectively, to permit flow of air from a source of vacuum pressure to vacuum recesses 32a_{l 5} 32a , 32a₃. The source of vacuum pressure can be controlled to selectively retain and release adhesive- backed elements 12 within vacuum recesses 32aι, 32a₂, 32a₃ for delivery to output web 14. In particular, a source of positive pressure can be intermittently coupled to vacuum recesses 32aι, 32a₂, 32a to expel adhesive-backed elements toward output web 14.

FIG. 6 is an end view of a vacuum manifold 85a for use with a vacuum drum 28 as shown in FIGS. 3-5. As shown in FIG. 6, vacuum manifold 85a may define a substantially circular face 93 that mounts onto an end of vacuum drum section 28a. An arcuate groove 95 is formed in face 93, and defines a flow path for air flowing from aperture 89 to ports 88. Groove 95 further provides a port 97 for inflow and outflow of air from manifold 85a. The source of vacuum pressure can be controlled to selectively retain and release adhesive-backed elements 12 from vacuum recesses in synchronization with the exchanges between vacuum drum 28, rotary cutting cylinder 22, and output web 14. FIG. 7 is a side view of rotary cutting cylinder 22 and illustrates rotary cutting cylinder sections 22a, 22b mounted along the length of drive shaft 26. As shown in FIG.

6, drum sections 22a, 22b include cutting elements 24a, 24b, respectively. Each cutting element 24a, 24b defines a die for cutting adhesive-backed elements 12 in a desired shape from input web 20. Each cutting element 24a, 24b may include vacuum ports 92, 94, respectively, that deliver vacuum pressure to retain adhesive-backed elements 12 cut from input web 20. Each rotary cutting cylinder section 22a, 22b may include a number of cutting elements 24a, 24b distributed about its respective circumference. While one cutting element 24a, 24b comes into position to cut an adhesive-backed element 12 from web 20, another moves toward a position for delivery of another adhesive-backed element to vacuum drum 28. A source of positive pressure may be intermittently coupled to ports

92, 94 to assist in expelling elements 12 for delivery to vacuum drum 28.

FIG. 8 is a cross-sectional end view of rotary cutting cylinder section 22a of FIG.

7. As shown in FIG. 8, rotary cutting cylinder section 22a may include a number of cutting elements 24aι-24a₇ distributed radially about the circumference of the section. In the example of FIG. 8, rotary cutting cylinder section 22a includes seven different cutting elements 24aι-24a₇. Vacuum ports 92 of each of cutting elements 24aι-24a₇ are coupled to internal vacuum channels 98 that, in turn, are coupled to a source of vacuum pressure, e.g., via a rotary manifold similar to that shown in FIG. 6 for vacuum drum 28.

The movement of vacuum drum 28 is alternating such that the vacuum drum receives and delivers adhesive-backed elements 12 in quick succession. For this reason, the rotation of vacuum drum 28 must be controlled for quick acceleration and deceleration. As an example, with three vacuum recesses 32aι, 32a₂, 32a₃ distributed about vacuum drum section 28a and seven cutting elements 24aι-24a₇ distributed about rotary cutting cylinder section 22a, the operation may proceed as follows. As web 20 is fed into the nip 21 between anvil roll 16 and rotary cutting cylinder 22, the anvil roller and rotary cutting cylinder are driven at substantially the same constant speed for approximately 30 degrees of the rotation.

During this time, rotary cutting cylinder 22 holds an adhesive-backed element 12 to one of cutting elements 24aι-24a₇. Anvil roll 16 and rotary cutting cylinder 22 then decelerate for approximately 10.7 degrees and then return to the constant speed for approximately another 10.7 degrees. While anvil roll 16 and rotary cutting cylinder 22 are running at the constant speed, vacuum drum 28 substantially matches the surface speed of rotary cutting cylinder 22 for approximately 30 degrees. During this 30 degrees, vacuum drum 28 holds an adhesive-backed element 12 received from rotary cutting cylinder 22 with vacuum pressure, while the rotary cutting cylinder releases the element, e.g., by application of positive pressure.

Vacuum drum 28 then accelerates to substantially match the surface speed of output web 14 within approximately 30 degrees. For approximately another 30 degrees, vacuum drum 28 substantially matches the surface speed of output web 14. During this time, adhesive-backed element 12 carried by one of vacuum recesses 32aι-32a on the surface of vacuum drum 28 is applied to web 14 by adhesive transfer. At the same time, vacuum drum 28 releases element 12, e.g., by application of positive pressure or cessation of application of negative pressure. Following transfer of adhesive-backed element 12 to output web 14, vacuum drum 28 decelerates over the next 30 degrees to substantially match the surface speed of rotary cutting cylinder 22. In this manner, vacuum drum 28 is prepared for receipt of another adhesive-backed element 12 from rotary cutting cylinder

22. The process continues and enables transfer of three or more adhesive-backed elements 12 per rotation of vacuum drum 28. FIG. 9 is a diagram of an adhesive-backed web 20 for cutting adhesive-backed elements 12 such as tape tabs. A pair of webs 20 is guided through the nip 21 between anvil roll 16 and rotary cutting cylinder sections 22a, 22b. Each web 20 is aligned with one of rotary cutting cylinder sections 22a, 22b. Cutting elements 24 carried by rotary cutting cylinder sections 22a, 22b cut adhesive-backed elements 12 from web 20, leaving holes 100 and scrim portion 102. As indicated by holes 100 in FIG. 9, the shape of adhesive-backed elements 12 can be substantially rectangular with rounded comers. Other shapes can be achieved, however, subject to the shapes of cutting elements 24, which can be determined based on the shapes desired for the end application. In the example of FIG. 9, adhesive-backed elements 12 may form closure tabs for diaper stock, and preferably have rounded corners.

FIG. 10 is a diagram illustrating placement of tape tabs on a diaper stock web. In the example of FIG. 10, adhesive-backed elements 12 in the form of tape tabs are positioned on opposite sides, e.g., right and left, of a diaper stock web 14. With reference to FIG. 10 and FIG. 2, vacuum drum sections 28a, 28b are positioned proximate the opposite side of diaper stock web 14 to deliver adhesive-backed elements 12 at precise intervals. A pair of elements 12 can be placed in each of a succession of sections 104, 106 that will form part of separate diapers, as indicated by dashed lines 108, 110.

FIG. 11 is a functional block diagram illustrating a control system for controlling an apparatus 10 as shown in FIG. 1. As shown in FIG. 11, movement of rotary cutting cylinder 22 and vacuum drum 28 is servo controlled to facilitate the matching of their surface speeds for transfer of adhesive-backed elements 12. Anvil roll 16 and buffing roll 38 also may be servo controlled, if desired. In the example of FIG. 11, rotary cutting cylinder motor 50 is controlled by a servo controller 1 12 that operates according to a control program stored in programmable memory 114. Similarly, vacuum drum motor 58 is controlled by a servo controller 116 that operates according to a control program stored in programmable memory 118. The programs stored in memories 114, 118 specify the acceleration and deceleration to be executed by motors 50, 58 in order to substantially match the surface speeds of rotary cutting cylinder 22 and vacuum drum 28 for transfer of adhesive-backed elements 12. In particular, servo controller 112 decelerates rotary cutting cylinder motor 50 when rotary cutting cylinder 22 is in position to cut an adhesive-backed element 12 from web 20, and accelerates motor 50 for transfer of the element to vacuum drum 28. For cutting, rotary cutting cylinder 22 substantially matches the surface speed of web 20. For transfer, rotary cutting cylinder 22 substantially matches a specified surface speed for interaction with vacuum drum 28. Servo controller 116 decelerates vacuum drum motor 58 to accept adhesive-backed elements 12 from rotary cutting cylinder 22, and accelerates motor 58 for transfer of elements 12 to web 14. Thus, vacuum drum 28 substantially matches the surface speed of rotary cutting cylinder 22 for receipt of elements 12, and substantially matches the surface speed of web 14 for delivery of the elements.

A programmer 120 permits modification or replacement of the programs stored in memories 114, 116 when conditions within apparatus 10 are changed. If the speed of web 14 or 20 is changed, for example, it is necessary to modify the control of servo motors 50, 58 to accommodate such changes. Similarly, program changes are necessary if the diameter of one of the rollers within apparatus 10 changes. A user interface 122 can be provided that permits a user to enter the desired changes, either in response to changes within apparatus 10 or on an ad-hoc basis. Programmer 120 and user interface 122 can be realized, for example, by a general purpose computer such as a workstation or personal computer, along with conventional input and output devices. In this manner, apparatus 10 provides controllers that are programmable to permit rotation of vacuum drum 28 or rotary cutting cylinder 22 at different surface speeds based on changes in the surface speeds of either of webs 14, 20. Closed loop control via encoder wheels and the like can be employed to permit servo controllers 112, 116 to respond to instantaneous changes in speed or position among the components of apparatus 10. A number of embodiments of the present invention have been described.

Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims

CLAIMS:

1. An apparatus for application of adhesive-backed elements, the apparatus comprising: a transfer element disposed between a supply of adhesive-backed elements and an article for receipt of one or more of the adhesive-backed elements; a drive mechanism that drives the transfer element to accept the adhesive-backed elements from the supply and deliver the adhesive-backed elements to the article; and a controller that controls the drive mechanism such that the transfer element moves at different speeds for the acceptance of the adhesive-backed elements from the supply and the delivery of the adhesive-backed elements to the article.

2. The apparatus of claim 1, further comprising: a first web transport mechanism that transports a first web of adhesive-backed material, the first web providing the supply of adhesive-backed elements; and a second web transport mechanism that transports a second web, the second web providing the article, wherein: the transfer element includes: a rotary cutting cylinder disposed adjacent the first web, the rotary cutting cylinder including cutting elements, and a vacuum drum disposed between the rotary cutting cylinder and the second web, the drive mechanism includes: a first drive mechanism that rotates the rotary cutting cylinder such that the cutting elements cut and remove the adhesive-backed elements from the first web, and a second drive mechanism that rotates the vacuum drum to remove the adhesive-backed elements from the rotary cutting cylinder and deliver the adhesive-backed elements to the second web, and the controller controls the second drive mechanism such that the vacuum drum rotates at different surface speeds for the removal of the adhesive-backed elements from the rotary cutting cylinder and the delivery of the adhesive-backed elements to the second web.

3. The apparatus of claim 2, wherein the controller controls the second drive mechanism such that the vacuum drum rotates at substantially the same surface speed as: the rotary cutting cylinder for the removal of the adhesive -backed elements, and the second web for the delivery of the adhesive-backed elements to the second web, wherein the surface speed of the second web is greater than the surface speed of the rotary cutting cylinder.

4. The apparatus of claim 3, wherein the controller controls the second drive mechanism such that the surface speed of the vacuum drum is greater for the delivery of the adhesive-backed elements to the second web than for the removal of the adhesive- backed elements from the first web.

5. The apparatus of claim 2, wherein the rotary cutting cylinder and the vacuum drum move at surface speeds such that the vacuum drum receives more than one of the adhesive-backed elements per each rotation of the vacuum drum.

6. The apparatus of claim 2, wherein the cutting elements of the rotary cutting cylinder are configured such that the adhesive-backed elements cut from the first web are non-rectangular.

7. The apparatus of claim 2, wherein the cutting elements of the rotary cutting cylinder are configured such that the adhesive-backed elements cut from the first web define substantially rectangular shapes with rounded corners.

8. The apparatus of claim 2, wherein the adhesive-backed elements are sized for use as diaper fastening tape, and the second web is formed from diaper cover material.

9. A method for application of adhesive-backed elements, the method comprising: moving a transfer element between a supply of adhesive-backed elements and an article for receipt of one or more of the adhesive-backed elements, whereby the transfer element accepts the adhesive-backed elements from the supply and delivers the adhesive- backed elements to the article; and controlling the movement of the transfer element such that the transfer element moves at different speeds for the acceptance of the adhesive-backed elements from the supply and the delivery of the adhesive-backed elements to the article.

10. The method of claim 9, further comprising: transporting a first web of adhesive backed material, the first web providing the supply of adhesive-backed elements; rotating a rotary cutting cylinder as part of the transfer element adjacent the first web, the rotary cutting cylinder including cutting elements, whereby the cutting elements cut and remove the adhesive-backed elements from the first web; transporting a second web, the second web providing the article; rotating a vacuum drum as part of the transfer element between the rotary cutting cylinder and the second web to remove the adhesive-backed elements from the rotary cutting cylinder and deliver the adhesive-backed elements to the second web; and controlling the movement of the transfer element at least in part by controlling the rotation of the vacuum drum such that the vacuum drum rotates at different surface speeds for the removal of the adhesive-backed elements from the rotary cutting cylinder and the delivery of the adhesive-backed elements to the second web.

11. The method of claim 10, further comprising controlling the rotation of the vacuum drum such that the vacuum drum rotates at substantially the same surface speed as: the rotary cutting cylinder for the removal of the adhesive-backed elements, and the second web for the delivery of the adhesive-backed elements to the second web, wherein the surface speed of the second web is greater than the surface speed of the rotary cutting cylinder.

12. The method of claim 10, further comprising controlling the rotation of the vacuum drum such that the surface speed of the vacuum drum is greater for the delivery of the adhesive-backed elements to the second web than for the removal of the adhesive- backed elements from the first web.

13. The method of claim 10, further comprising moving the rotary cutting cylinder and the vacuum drum at surface speeds such that the vacuum drum receives more than one of the adhesive-backed elements per each rotation of the vacuum drum.

14. The method of claim 10, wherein the cutting elements of the rotary cutting cylinder are configured such that the adhesive-backed elements cut from the first web are non-rectangular.

15. The method of claim 10, wherein the cutting elements of the rotary cutting cylinder are configured such that the adhesive-backed elements cut from the first web define substantially rectangular shapes with rounded corners.

16. The method of claim 10, wherein the adhesive-backed elements are sized for use as diaper fastening tape, and the second web is formed from diaper cover material.