AU715601B2 - Rotary sealing system - Google Patents

Description

S F Ref: 385072D1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

r r r r r r r r r Name and Address of Applicant: Kimberly-Clark Worldwide, Inc.

401 North Lake Street Neenah Wisconsin 54957-0349 UNITED STATES OF AMERICA Actual Inventor(s): Gregory John Rajala, Steven Craig Gehling and Dean Edward Paszek Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Invention Title: Rotary Sealing System The following statement is a full description of this invention, including the best method of performing It known to me/us:- 5845 ROTARY SEALING SYSTEM This invention relates to apparatus and methods for applying thermal energy to workpieces, such as for bonding, sealing, cutting and the like of the workpieces. More particularly, the present invention relates to an apparatus and method for applying ultrasonic energy to workpieces such as disposable diapers, training pants, feminine care products, feminine care and incontinence garments or the like.

Use of mechanical vibration produced at an ultrasonic frequency to weld thermoplastics, and to emboss and form plastics is a well-established industrial process. The physical principles underlying this technology have important relations to the invention described herein and therefore merit brief review and discussion.

To obtain significant vibrational motion, most ultrasonic systems are operated at one of their frequencies of resonance. Both the ultrasonic generator and the ultrasonic horn are designed to resonate at the same frequency, in which case the vibration produced by the generator is communicated to the horn. Since the horn is tuned to the same frequency as the generator, the horn expands and contracts along its length in concert with the imposed motion of the vibration generator.

The motion produced at the free face of the horn is then reciprocal, or back and forth in a surface perpendicular to the surface of the horn, with an amplitude determined by the electrical voltage applied to the crystals of the vibration generator. It is known to condition the vibrations produced by the generator before the vibrations are communicated to the horn, including incorporating amplification devices and phase change devices into the sequence of elements so used.

Oone problem encountered in applying resonant ultrasonic vibration to continuous processes is the limitation on horn width.

Although the horn executes motion principally of contraction and .0 extension along its working surface, the wider the horn, e.g. the longer its working surface, typically the greater the variation in the amplitude of the vibrations along the length of the working surface. Accordingly, in general, use of ultrasonic energy to process workpieces in a continuous web has been limited to two types of processes.

The first type of process is one where a rotary ultrasonic horn disposed in a fixed location applies ultrasonic energy, against an underlying anvil, at essentially a line along a workpiece travelling, in a longitudinal direction along the workpiece, past the rotating horn. This first type of process is illustrated by United States Patent 3,222,235 to Buchner.

The second type of process is one where one or more. stationary flat planar surface or plunge-type, as they are commonly referred, ultrasonic horns extend across the width of the web and apply ultrasonic energy to all or selected parts of the web as the web passes between the stationary horns and corresponding underlying anvils, as illustrated by United States Patents 3,939,033 to Grgach et al and 3,733,238 to Long et al, respectively. The plunge-type may imply its motion, however, the horn may, in fact, be stationary and the web moved to it.

In a first modification of the second type of process, United States Patent 4,713,132 to Abel et al teaches mounting a series 25 of flat planar surface horns for rotation about fixed axes disposed about a rotating anvil drum, and rotating the horns such that the horns rotate into and out of contact with the workpieces on the web.

In a second modification of the second type of process, United States Patent 4,650,530 to Mahoney et al teaches folding the web of workpieces about the periphery of a rotating disc, and bringing ultrasonic horns, and corresponding anvils into alignment with the workpieces, as they rotate on the disc. The 35 horns and anvils are of the flat planar surface arrangement. The horns and anvils rotate with the disc, and the ultrasonic system operates on the workpieces by bringing respective sets of horn and anvil against the respective workpiece at a locus in a free space between'radially extending protrusions on the disc. Thus the disc which carries the workpieces does not participate in the application of ultrasonic energy, and the reciprocating motion of the ultrasonic horns operates in a direction coincident with the direction of extension of the axis of the rotating disc which carries the workpieces.

A second problem with flat planar surface ultrasonic horns is that, in order to obtain uniform application of the ultrasonic energy along the length of the horn, the spacing of the horn from the anvil must be aligned in two dimensions along the face of the horn such that the working surface of the horn is e.g. precisely parallel with the working surface of the anvil. Especially where there is e.g. any continuing motion of the horn or the anvil other than the ultrasonic vibrations, for example rotation of either or both of the horn or anvil, such precise alignment becomes a dynamic problem, requiring constant monitoring and repeated adjustment of the spacing between the horn and the anvil.

It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.

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i C [N:\LIBLL]02342:KEH There is disclosed herein a method of applying energy to a workpiece, the method comprising the steps of: rotating a drum about a first axis of rotation in a given direction, the drum having a circumferential outer working surface, a first energy application device being mounted on the drum at the outer working surface and extending transverse to the direction of rotation of the drum; providing a second energy application device, mounted for rotation with the drum; while rotating the drum, moving the second energy application device in a direction transverse to the direction of rotation of the drum and thereby extending the second energy application device over the first energy application device and operating the first and second energy application devices in combination and thereby applying energy to the workpiece at a point moving progressively across the workpiece; and while rotating the drum, withdrawing the second energy application device from over the first energy application device.

Preferably, the first energy application device comprises a first ultrasonic application device, and the second energy application device comprises a second S ultrasonic application device, and thereby applying ultrasonic energy to the workpiece.

00° 0 00 0 *00 CC [N:\LIBLL]02342:KEH Preferably, the energy applied comprises thermal energy generated by electrical resistance.

Preferably, the above disclosed method includes applying ultrasonic energy to the workpiece through the second energy application device.

Preferably, the above disclosed method includes extending the second energy application device over the first energy application device, and subsequently withdrawing the second energy application device from over the first energy application device, during each rotation of the drum.

Preferably, the above disclosed method includes extending the second energy application device over the first energy application device, and applying pressure on a workpiece on the first energy application device, and thereby applying energy to the workpiece.

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[N:\LIBLL102342:KEH Preferably, the above disclosed method includes traversing the second energy application device along an energy application path over the first energy application device and over a workpiece on the first energy application device, and simultaneously applying pressure and ultrasonic energy to the workpiece disposed on the first energy application device, and thereby accomplishing work at the point moving progressively across the workpiece while so traversing the energy application path.

Preferably, the first energy application device comprising an anvil, the second energy application device comprising a rotary ultrasonic horn comprising a wheel mounted for rotation about a second axis, the method comprising applying ultrasonic energy to the workpiece at the point moving progressively across the workpiece as the second energy application device traverses the energy application path.

Preferably, the above disclosed method includes applying pressure, through the second energy application device to the workpiece, as the second energy application device traverses an energy application path.

Preferably, the energy application path including an outgoing segment wherein the second energy application device is being extended over the first energy application device and an incoming segment wherein the second energy application device is being withdrawn from over the first energy application device, the method further comprising controlling the second energy application device and thereby applying pressure through 20 the second energy application device at the point moving progressively across the workpiece on one of the segments of the energy application path and withholding the pressure on the other of the segments of the energy application path.

°o o° [N:\LIBLL]O2342:KEH -7- Preferably, the energy application path including an outgoing segment wherein the second energy application device comprises a rotary ultrasonic horn being extended out over the first energy application device and an incoming segment wherein the rotary ultrasonic horn is being withdrawn from over the anvil, the method further comprising controlling the rotary ultrasonic horn and thereby applying pressure through the rotary ultrasonic horn to the workpiece on one of the segments of the energy application path and withholding the pressure on the other of the segments of the energy application path.

Preferably, the first energy application device comprising first and second anvils mounted at different radial locations about the outer working surface of the drum, and the second energy application device comprising first and second ultrasonic horns, the first and second ultrasonic horns being mounted for rotation with the drum and over respective ones of the first and second anvils, the method including controlling operation of the first and second ultrasonic horns and thereby beginning to extend a respective one of the first and second ultrasonic horns over a respective first or second anvil when the respective first or second ultrasonic horn is disposed at a locus i corresponding to a first angle measured with respect to a reference line passing through the first axis, the method including rotating the drum, and subsequently S beginning to withdraw the respective ultrasonic horn from over the respective anvil S. S

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S °S ooooo [N:\LIBLL]02342:KEH such that the respective ultrasonic horn is fully withdrawn from over the respective anvil when the drum has rotated such that the respective ultrasonic horn is disposed at a second angle measured with respect to the reference line passing through the first S axis, and wherein the same angles and measured with respect to the reference line passing through the first axis, apply for each of the ultrasonic horns.

Preferably, the above disclosed method includes placing a workpiece onto a working station of the outer working surface at a placing station located at an angle "P" measured with respect to a reference line passing through the first axis; rotating the drum; and removing the workpiece from the drum at a removing station; and while rotating the drum, controlling movement of the second energy application device and thereby extending the second energy application device over the drum and correspondingly over the workpiece; and withdrawing the second energy application device from over the drum such that withdrawal of the second energy application device is complete, and the second energy application device remains withdrawn from over the drum while the working station of the outer working surface traverses from the removing station to the placing station.

44*44* 4 .i 4 4 [N:\LIBLL102342:KEH There is further disclosed herein a system for applying thermal energy to a workpiece, comprising: a drum, mounted for rotation about a first axis in a given direction, said drum having a circumferential outer working surface; a first energy application device, mounted on said drum at said outer working surface, and extending transverse to the direction of rotation of said drum; and a second energy application device, mounted for rotation with said drum, and for moving in a direction transverse to the direction of rotation of said drum to thereby extend over said first energy application device, and operate hn combination with said first energy application device, to apply energy to the workpiece during rotation of said drum, and for subsequently withdrawing from over said first energy application device during rotation of said drum.

There is further disclosed herein a method of applying energy to a workpiece, the method comprising the steps of: rotating a drum about a first axis of rotation in a given direction, the drum having a circumferential outer working surface, a first energy application device being mounted on the drum at the outer working surface and extending transverse to the f direction of rotation of the drum; providing a second energy application device, mounted for rotation 20 with the drum; 9 9* 9* 9 *0Soo9 lDD m [N:\LIBLL02342:KEH while rotating the drum, moving the second energy application device in a direction transverse to the direction of rotation of the drum and thereby extending the second energy application device over the first energy application device and operating the first and second energy application devices in combination and thereby applying energy to the workpiece at a line moving progressively across the workpiece; and while rotating the drum, withdrawing the second energy application device from over the first energy application device.

Preferably, the energy applied comprises thermal energy.

Preferably, the first energy application device comprises a first ultrasonic application device, and the second energy application device comprises a second ultrasonic application device, and thereby applying ultrasonic energy to the workpiece.

Preferably, the first ultrasonic application device comprises an anvil, and the second ultrasonic application device comprises a rotary ultrasonic horn, the method including applying pressure and ultrasonic energy to the workpiece at the line moving progressively across the workpiece as the ultrasonic horn traverses an energy application path.

Preferably, the ultrasonic horn comprising a rotary ultrasonic horn, the method including rotating the rotary ultrasonic horn about a second axis transverse to the first 0 20 axis of the drum as the ultrasonic horn traverses the energy application path.

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a perspective view of a workpiece which may be made using methods and apparatus of this invention.

0S S oo °S S [N:\LIBLL]02342:KEH Fig. 2 is a top view of a finished workpiece blank, as a workpiece in a continuous web, from which the workpiece of Fig. 1 can be made.

Fig. 3 is a pictorial view, with parts missing and parts cut away, showing a thermal energy system of the invention.

Fig. 4 is a cross-section of the thermal energy system of Fig. 3, taken at planar section 4-4 of Fig. 3.

Fig. 5 is a schematic representation of an end elevation view of the thermal energy system of Fig. 3.

Fig. 6 is a top view of the first thermal energy application device, taken at 6-6 of Fig. 3.

Fig. 7 is a side view of the first thermal energy application device of Fig. 6.

Fig. 8 is a cross-section as in Fig. 4, of a second embodiment of thermal energy systems of the invention.

The following detailed description of the illustrated embodiments 2 is made in the context of making disposable type garments such as diapers, training pants, feminine care products, incontinence garments, and the like, and includes apparatus and methods for joining two superposed spunbonded polypropylene elasticized composite webs, e.g. 23.74 g per m 2 (0.7 ounce per square yard) 3c" each, by producing ultrasonic welds at spaced locations extending across the webs in directions transverse (cross machine oeos •h wb direction) to the direction of travel of the webs in the processing apparatus (with machine direction). The specific context is the production of disposable type garments in a continuous combined web, where the garment preforms in the web extend transverse to the web, with the waist portions of the garments extending along the machine direction of the web, and S the front and back portions of the garments being on opposing sides of the web. In the embodiments illustrated, the welds join the superposed webs at locations generally corresponding to the ultimate locations of side seams in the finished garments.

It is generally known to make a garment 10 of the type shown in Fig. 1. Such garments typically comprise an assemblage of two or more layers or partial layers of different materials or may comprise substantially the same materials, along with other elements. Typically, the material is a woven or non-woven fabric, or a polymer film. Elastic may be used at the waist 12, in the body portion 14, and around the leg openings 16.

In this context, as in most such processes for fabricating the garment as at 10, a blank 18 such as that shown in Fig. 2 is first made as part of a continuously processed composite web of materials. After the blank 18 is fully fabricated, the -sideseams are formed and the garment 10 is severed from the web either as a blank 18, -fully finished or partially finished, or as a fully formed garment article.

The process contemplated by the invention forms the welds 22 adjacent the adjoining edges of leading and trailing blanks 18A and 18B as illustrated in Fig. 2. In forming such transverse welds 22 using known technology, it is difficult to obtain uniform application of thermal energy across the entire width of the web, whereby the welds 22 may exhibit less than the desired uniformity. The apparatus and methods disclosed hereinafter "2 provide a novel approach to achieving predictably uniform such welds 22 in the blanks 18 being formed.

Figs. 3-7 illustrate one embodiment of a thermal system of the invention. Said thermal energy system may be comprised of any device by which the transfer of thermal energy is sufficient to S weld the material together, such as electrical resistance devices such as continuously heated or intermittently heated impulse type devices, or induction heated components. The preferable thermal energy source is by the use of ultrasonics. As seen there, an ultrasonic system 24 includes a work drum 26 mounted on an outer shaft 25, for rotation about an axis 28 passing through a fixed inner shaft generally designated as 30. The work drum 26 has an outer working surface 32 perforated and otherwise adapted in conventional manner (not shown) to provide suction through the outer working surface of the work drum 26, to hold a web 33 of 13 material workpieces which, when all processing is finished, can be assembled as blanks 18 into the garment articles A plurality of anvil bars 34 (six are shown) are mounted to the work drum 26, spaced uniformly about the outer circumference of the work drum 26, and extend transversely across the width dimension of the outer working surface 32 of the work drum 26.

The anvil bars 34 are flush with the outer working surface 32, such that outer surfaces 36 of the anvil bars 34 generally comprise a continuation of the outer working surface 32 of the work drum 26.

A support drum 38 is secured to the work drum 26, and mounted for rotation with the work drum. Referring to Fig. 4, support drum 38 is secured to work drum 26 at interface wall 40. The combination of the work drum 26 and the support drum 38 are mounted to the outer shaft 25. Outer shaft 25 is mounted to the fixed inner shaft 30 by bearings 42 and 44. An outer wall 46 of the support drum 38 is secured to end flange 48 through end wall 49. End flange 48 is secured to driven shaft 50 which is driven off the line shaft, not shown, of the processing line. Driven shaft 50 is mounted to ground through bearing 52. Accordingly, the work drum 26, the support drum 38, and the end flange 48 are all supported by the combination of bearings 42, 44, and 52, and all rotate in unison about fixed inner shaft 30 and the axis 28.

Cam drum 54 is fixedly secured to fixed inner shaft 30, such that it does not rotate with the combination of work drum 26, support drum 38, and end flange 48. Cam rib 56 is mounted on the outer s: wall 58 of the cam drum 54, and extends about the entire circumference of the outer wall 58 of the cam drum 54. Cam rib 56 is seen in dashed outline in Fig.S 4 and 8. A portion of the cam rib 56 is seen through a cutaway portion of the outer wall 46 of the support drum in Fig. 3.

Six pairs of carriage support tracks 60 are secured to the outer wall 58 of cam drum 54, corresponding in number, and in general location, to respective anvil bars 34 on the outer working surface 32 of work drum 26. A carriage 62 is mounted to each pair of carriage support tracks 60, for sliding engagement with the carriage support tracks 60, along the lengths of the respective carriage support tracks 60, as will be illustrated further hereinafter.

Referring now to Figs. 6 and 7, an ultrasonic support subassembly 64 is mounted to each carriage 62 at pivot pin 66. In the ultrasonic support subassembly 64, support arm 68 extends from pivot pin 66, toward outer working surface 32 of the work drum 26, and supports, at its remote end, a rotary ultrasonic horn and ultrasonic generator 72. Support arm 68 is fixedly secured to control arm 74. Control arm 74 is operated by double acting air cylinder 76, acting through pivot pin 66 and control arm 74, to pivot the ultrasonic horn 70 about pivot-pin 66 and thereby to raise and lower the ultrasonic horn 70 with respect to the outer working surface 32 of work drum 26. Thus, the ultrasonic support subassembly 64 comprises pivot pin 66, support arm 68, and control arm 74.

Compressed air is supplied to the air cylinder 76 from pneumatic control box 78. See Fig. 4. Compressed air is supplied to the pneumatic control box 78 through supply line 80, which is connected, through a conventional rotary pneumatic coupling to fixed shaft 30. Air is supplied through the center of fixed shaft 30 from a supply line 82.

Electric power is supplied to the ultrasonic system 24 through slip rings 84, and is communicated to the ultrasonic generators 72 through supply line 86.

Programmable limit switch 88 is also mounted to the driven shaft for purpose to be discussed hereinafter. Output of the programmable limit switch 88 is fed to the control box 78 through electric line It is contemplated that the operation and functions of the invention have become fully apparent from the foregoing description of elements and their relationships with each other, oooo S but for completeness of disclosure, the usage of the invention will be briefly described.

Turning now to Fig. 4, driven shaft 50 turns end flange 48, work drum 26, support drum 38 and its supported carriages 62, ultrasonic support subassemblies 64, ultrasonic horns 70, and generators 72, continuously at a steady speed of rotation. An incoming turning roll 92 is disposed at a placing station, relative to a reference line through axis 28, at an angle "p11 on the circumference of the work drum 26. A web 33 of workpieces or other material is fed, in the direction indicated by arrow 93 about incoming turning roll 92, and is thereby drawn into engagement with the working surface 32 of the work drum 26, at the nip formed between work drum 26 and turning roll 92, while the work drum is rotating in the direction indicated by the arrow 94. The web 33 is generally drawn about the circumference of work drum 26 at its outer working surface from incoming turning roll 92 until it reaches the outgoing turning roll--96, at the removing station disposed at an angle on the circumference of the work drum 26. At outgoing turning roll 96, the web 33 turns about the turning roll 96 as indicated there by the web 33, and is thus removed from the work drum and exits the process of interest in this invention.

In general, as the invention is practiced, the ultrasonic horns are continuously activated, resonating at their designed frequencies.

o Turning to the combination of Figs. 3-7, a slot opening 98 extends through the outer wall 46 of support drum 38 adjacent each carriage support track 60. A pair of cam followers 100 extends downwardly from each respective carriage, through slot opening 98, and engages the rib cam 56. Accordingly, as the working drum 26 and support drum 38 rotate on axis 28, about the 0* stationary cam drum 54, the engagement of the cam followers 100 with the rib cam 56 causes the carriages 62 to move alternately toward and away from the outer working surface 32 of the work drum 26. Each carriage 62 thus makes one complete round trip motion, toward the work drum 26 and away from the work drum 26, for each 360 degree rotation of the work drum 26. Accordingly, and now referring to Figs. 3-5, the carriage 62A at the 12 o'clock position on support drum 38 is fully extended toward the work drum 26; and the carriage 62B at the 6 o'clock position on support drum 38' is fully withdrawn away from the work drum 26.

16 As the carriages 62 extend toward the work drum 26, the respective ultrasonic horns 70 extend over the outer working surface 32 of the work drum 26, and over the corresponding anvil bar 34. As the carriages 62 withdraw from the work drum 26, the respective ultrasonic horns 70 withdraw from over the outer working surface 32 of the work drum 26.

An ultrasonic horn 70 is considered fully withdrawn from over the outer working surface 32 when the remote outer edge 101 of the combination of the ultrasonic support assembly 64, horn 70, and generator 72, passes inwardly of the inner edges 102 of turning rolls 92 and 96. See Fig. 4, where the horn 70 on carriage 62B is fully withdrawn, and has moved still further awdy from the work drum 26 than the defined "fully withdrawn" position.

Accordingly, "fully withdrawn" comprehends a range of positions of the outer edge 101 disposed inwardly of the inner edges 102 of the turning rolls 92 and 96, and is not limited to the innermost position where the carriage 62 is disposed in its most remote position with respect to the work drum 26.

As each carriage -62 extends toward the work drum 26, and the respective ultrasonic horn 70 is correspondingly disposed over the outer working surface 32, programmable limit switch 88 S signals the pneumatic control box 78, thus activating and extending the ram 103 on the respective air cylinder 76 to thus move the respective resonating ultrasonic horn 70 downwardly, as shown by the double headed arrow indicated as 104 in Fig. and into contact with the workpiece being carried in the web 33 at the respective work station 106 defined at each respective anvil 30 bar 34. The rotary ultrasonic horn 70 exerts a downward force on the workpiece against the supporting resistance of the anvil bar 34. The amount of downward force is controlled by the force exerted at air cylinder 76.

With the resonating rotary ultrasonic horn 70 thus exerting a downward force on the workpiece, the circular rotary horn 70 is allowed to rotate about an axis 110 as it provides an effective application of ultrasonic energy to the workpiece at a point 112 moving progressively across the workpiece as the ultrasonic horn 70 traverses across the working surface 32 in an energy application path 108. As indicated in Fig. 4, the energy 17 application path can extend less than all the way across the web 33; or can extend all the way across the web 33, depending on what work is to be performed by the ultrasonic' energy, and the lengths of carriage support tracks 60 and support arm 68.

Preferably, the ultrasonic horn 70 is forced downwardly into working contact with the workpiece while the horn 70 is traversing the outgoing segment of the energy application path 108. When the respective ultrasonic horn 70 reaches the outer extremity of the outgoing segment of the energy application path 108, limit switch 88 senses the respective associated angular position of the working station 106 with respect to axis 28, and signals the pneumatic control box 78, lifting the horn 70 from the workpiece as the horn 70 is being withdrawn from over the workpiece on the (reverse direction) incoming segment of the energy application path 108. Referring to Fig. 5, the horn begins being extended over the drum 26, namely crossing the inner edge 102 of the turning rolls 92, 96 at an angle on the outer circumference of the work drum 26, and is fully withdrawn from over the outer working surface 32 at an angle on the outer circumference of the work drum 26. Referring to Fig. 5, it is o S• seen that the respective horn assembly is fully withdrawn before the respective workpiece in web 33 arrives at the turning roll 96 where the workpiece and web 33 are removed from the work drum 26.

Similarly, the horn assembly, comprising horn 70, generator 72, and ultrasonic support subassembly 64, remains fully withdrawn, and does not begin being extended over the outer working surface 32 until the horn assembly has passed the incoming turning roll 92 and the outer working surface 32 is again becoming engaged with the incoming web 33 of workpieces.

The working drum 26 thus rotates continuously, accompanied by the S: ultrasonic horns 70. Workpieces enter the ultrasonic system 24 as they are placed on the work drum 26 as part of web 33, and traverse the working path 114 between the placing station at angle and the removing station at an angle while the ultrasonic application devices, as horns 70 and anvils 34, form the welds 22. Each horn 70 thus extends across the outer working surface 32 at the respective anvil 34 to make a weld 22 in the workpiece with each rotation of the work drum 26. The welds 22 extend in the cross machine direction. At any given time, the combined apparatus can support performing welding, cutting, or the like operations on substantially as many workpieces as there are work stations 106, and corresponding workpieces, on the drum 26 between the turning rolls 92 and 96, allowing sufficient clearance for "full withdrawal" of the respective horns 70 from the outer working surface 32 so that the web 33 with the finished workpieces can be removed at turning roll 96.

Suitable rotary ultrasonic horns 70 are, for example, those taught in United States Patent 5,110,403 to Ehlert, herein incorporated by reference for its teaching with respect to suitable such rotary ultrasonic horns 70. Suitable ultrasonic generators 72, and other related ultrasonic equipment, is available from a variety of suppliers, for example, Sonic Power Company, Danbury, Connecticut.

Fig. 8 shows a second embodiment of the invention wherein the ultrasonic horn 70 and the cooperating anvil 34 are disposed in physically reversed locations from the embodiment of Figs. 3-7.

Thus, comparing the embodiment of Fig. 8 to the embodiment S described in more detail with respect to Figs. 3-7, in Fig. 8, a pair of conventional plunge-type ultrasonic horns 170 are mounted in the work drum 26 in place of the anvil bar 34. As many plunge S. type horns 170 can be used as necessary to span the full width of the energy application path 108. Correspondingly, a rotary anvil 134 is mounted to the ultrasonic support assembly 64 in place of the rotary ultrasonic horn In use, the ultrasonic horns 170 are preferably activated continuously during operation of the process. Work drum 26 and S support drum 38 rotate continuously as described above. As the drums rotate, the anvil 134 is extended over the working surface, and forced into working contact with the workpieces by air cylinder 76 as the anvil 134 traverses the outgoing segment of the energy application path 108, and lifts the anvil 134 from the workpiece as it traverses the incoming segment of the energy application path 108. The significant difference is that the locations of the ultrasonic horn 170 and the anvil 134 are reversed, while the physical movement role of extending over the outer working surface 32 and subsequently withdrawing remains embodied in the elements mounted on carriage 62. Accordingly, 19 the ultrasonic application device mounted in the outer working surface 32 of the work drum 26 is the device supplying the ultrasonic energy, rather than the ultrasonic application device mounted on the ultrasonic support subassembly 64.

Alternatively, other energy application devices may be substituted for the ultrasonic devices. Such devices include electric resistance heating elements, electric indicator elements, and fluid heated elements.

Having thus described the invention in full detail, it will be readily apparent that various changes and modifications may be made without departing from the spirit of the inventi6n. All such changes and modifications are contemplated as being within the scope of the present invention, as defined by the following claims.

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Claims (22)

1. A method of applying energy to a workpiece, the method comprising the steps of: rotating a drum about a first axis of rotation in a given direction, the drum having a circumferential outer working surface, a first energy application device being mounted on the drum at the outer working surface and extending transverse to the direction of rotation of the drum; providing a second energy application device, mounted for rotation with the drum; while rotating the drum, moving the second energy application device in a direction transverse to the direction of rotation of the drum and thereby extending the second energy application device over the first energy application device and operating the first and second energy application devices in combination and thereby applying energy to the workpiece at a point moving progressively across the workpiece; and while rotating the drum, withdrawing the second energy application device from over the first energy application device.

2. A method as in claim 1, wherein the first energy application device S comprises a first ultrasonic application device, and the second energy application device comprises a second ultrasonic application device, and thereby applying ultrasonic energy to the workpiece.

A method as in claim 1 or claim 2, wherein the energy applied comprises thermal energy generated by electrical resistance.

4. A method as in any one of claims 1 to 3, including applying ultrasonic energy to the workpiece through the second energy application device.

5. A method as in any one of claims 1 to 4, including extending the second energy application device over the first energy application device, and subsequently withdrawing the second energy application device from over the first .e energy application device, during each rotation of the drum.

6. A method as in any one of claims 1 to 5, including extending the second energy application device over the first energy application device, and applying pressure on a workpiece on the first energy application device, and thereby applying energy to the workpiece.

7. A method as in claim 1, claim 2 or any one of claims 4 to 6, including traversing the second energy application device along an energy application path over the first energy application device and over a workpiece on the first energy application device, and simultaneously applying pressure and ultrasonic energy to the workpiece disposed on the first energy application device, and thereby accomplishing work at the [N:\LIBLL02342:KEH point moving progressively across the workpiece while so traversing the energy application path.

8. A method as in claim 1 or claim 2 or any one of claims 4 to 6, the first energy application device comprising an anvil, the second energy application 5 device comprising a rotary ultrasonic horn comprising a wheel mounted for rotation about a second axis, the method comprising applying ultrasonic energy to the workpiece at the point moving progressively across the workpiece as the second energy application device traverses the energy application path.

9. A method as in any one of claims 1 to 8, including applying pressure, through the second energy application device to the workpiece, as the second energy application device traverses an energy application path.

A method as in any one of claims 7 to 9, the energyapplication path including an outgoing segment wherein the second energy application device is being extended over the first energy application device and an incoming segment wherein the second energy application device is being withdrawn from over the first energy application device, the method further comprising controlling the second energy application device and thereby applying pressure through the second energy application device at the point moving progressively across the workpiece on one of the segments S of the energy application path and withholding the pressure on the other of the 20 segments of the energy application path.

11. A method as in any one of claims 7 to 10, the energy application path including an outgoing segment wherein the second energy application device comprises S•a rotary ultrasonic horn being extended out over the first energy application device and an incoming segment wherein the rotary ultrasonic horn is being withdrawn from over the anvil, the method further comprising controlling the rotary ultrasonic horn and thereby applying pressure through the rotary ultrasonic horn to the workpiece on one of the segments of the energy application path and withholding the pressure on the other of the segments of the energy application path.

A method as in claim 1, the first energy application device comprising 30 first and second anvils mounted at different radial locations about the outer working surface of the drum, and the second energy application device comprising first and second ultrasonic horns, the first and second ultrasonic horns being mounted for S rotation with the drum and over respective ones of the first and second anvils, the method including controlling operation of the first and second ultrasonic horns and thereby beginning to extend a respective one of the first and second ultrasonic horns over a respective first or second anvil when the respective first or second ultrasonic horn is disposed at a locus corresponding to a first angle measured with respect to a reference line passing through the first axis, the method including rotating the drum, [N:\LIBLL]02342:KEH a 22 and subsequently beginning to withdraw the respective ultrasonic horn from over the respective anvil such that the respective ultrasonic horn is fully withdrawn from over the respective anvil when the drum has rotated such that the respective ultrasonic horn is disposed at a second angle measured with respect to the reference line passing through the first axis, and wherein the same angles and measured with respect to the reference line passing through the first axis, apply for each of the ultrasonic horns.

13. A method according to any of claims 1 to 12, including placing a workpiece onto a working station of the outer working surface at a placing station located at an angle measured with respect to a reference line passing through the first axis; rotating the drum; and removing the workpiece from the drum at a removing station; and while rotating the drum, controlling movement of the.-second energy application device and thereby extending the second energy application device over the drum and correspondingly over the workpiece; and withdrawing the second energy application device from over the drum such that withdrawal of the second energy application device is complete, and the second energy application device remains withdrawn from over the drum while the working station of the outer working surface traverses from the removing station to the placing station.

14. A system for applying thermal energy to a workpiece, comprising: a drum, mounted for rotation about a first axis in a given direction, said drum having a circumferential outer working surface; a first energy application device, mounted on said drum at said outer working surface, and extending transverse to the direction of rotation of said drum; and a second energy application device, mounted for rotation with said drum, and for moving in a direction transverse to the direction of rotation of said drum to thereby extend over said first energy application device, and operate in combination o with said first energy application device, to apply energy to the workpiece during rotation of said drum, and for subsequently withdrawing from over said first energy i application device during rotation of said drum. o

15. An energy system for applying thermal energy to a workpiece, the energy system being substantially as hereinbefore described with reference to the accompanying drawing.

16. A method for applying thermal energy to a workpiece, the method being substantially as hereinbefore described with reference to the accompanying drawings.

17. A method for applying thermal energy to a workpiece as in any one of claims 1 to 11 using an energy system as claimed in claim 14. [N:\LIBLL]02342:KEH *i 23

18. A method of applying energy to a workpiece, the method comprising the steps of: rotating a drum about a first axis of rotation in a given direction, the drum having a circumferential outer working surface, a first energy application device 5 being mounted on the drum at the outer working surface and extending transverse to the direction of rotation of the drum; providing a second energy application device, mounted for rotation with the drum; while rotating the drum, moving the second energy application device in a direction transverse to the direction of rotation of the drum and thereby extending the second energy application device over the first energy application device and operating the first and second energy application devices in combinatian and thereby applying energy to the workpiece at a line moving progressively across the workpiece; and while rotating the drum, withdrawing the second energy application device from over the first energy application device.

19. A method as in claim 18, wherein the energy applied comprises thermal energy.

20. A method as in claim 18, wherein the first energy application device eo.. 20 comprises a first ultrasonic application device, and the second energy application device 0. comprises a second ultrasonic application device, and thereby applying ultrasonic energy to the workpiece.

21. A method as in claim 20, wherein the first ultrasonic application device comprises an anvil, and the second ultrasonic application device comprises a rotary ultrasonic horn, the method including applying pressure and ultrasonic energy to :the workpiece at the line moving progressively across the workpiece as the ultrasonic horn traverses an energy application path.

22. A method as in claim 21, the ultrasonic horn comprising a rotary S ultrasonic horn, the method including rotating the rotary ultrasonic horn about a second axis transverse to the first axis of the drum as the ultrasonic horn traverses the energy application path. Dated 30 December, 1998 Kimberly-Clark Worldwide, Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [N:\LIBLL]02342:KEH