Method and apparatus for applying a curved elastic to a moving web

A distinctive method and apparatus for applying an elastic member onto a moving substrate along a selected curvilinear location includes a transporting mechanism for moving the substrate along a selected substrate path. A rotatable nip roll contacts the elastic member to place the elastic member onto the substrate along the curvilinear location. A guiding mechanism delivers the elastic member across a free-span distance directly onto the nip roll while selectively changing a lateral positioning of the elastic member relative to a cross direction of the invention. A conveying mechanism directs the elastic member along a selected elastic path into the guiding mechanism, and an elastic supplying mechanism provides the elastic member to the conveying mechanism. In one aspect of the invention, a bonding mechanism provides an adhesive in an arrangement which secures the elastic member to the substrate along the curvilinear location. The adhesive arrangement is configured to substantially avoid contact with the nip roll.

FIELD OF THE INVENTION 
The present invention relates to a method and apparatus for applying an 
elastic member in a curved configuration onto a moving substrate web. More 
particularly, the present invention relates to a method and apparatus for 
applying elastic members in a curved configuration at each of the leg 
opening regions of a disposable absorbent article, such as a disposable 
diaper. 
BACKGROUND OF THE INVENTION 
Limited use absorbent articles, such as disposable diapers, have 
incorporated elasticized gathers at the leg openings of the article. The 
leg openings are positioned at the lateral side margins of the article, 
and can be elasticized with a single elastic member or with multiple 
elastic members. For example, see U.S. Pat. No. 4,050,462 issued Sep. 27, 
1977, to Woon et al. 
Various techniques have been developed for applying multiple elastic 
strands onto a substrate. For example, see U.S. Pat. No. 4,666,542 issued 
May 19, 1987, to DeJonckheere; U.S. Pat. No. 4,626,305 issued Dec. 2, 
1986, to Suzuki et al.; and U.S. Pat. No. 4,525,229 issued Jun. 25, 1985, 
to Suzuki et al. 
It has been desirable to employ curved elastic members which better follow 
the contours of the leg openings formed in the side margins of disposable 
absorbent garments. For example, techniques for applying an elastic member 
in a curved pattern, along the lengths of a substrate web have been 
described in U.S. Pat. No. 4,293,367 issued Oct. 6, 1981, to Klasek et 
al.; and U.S. Pat. No. 4,915,676 issued Apr. 10, 1990, to Rajala et al. 
Conventional techniques, such as those described above, have not provided 
an adequate system for efficiently placing an elastic member across a 
desired curvilinear location on the surface of a moving substrate. Typical 
conventional techniques have incorporated complicated web paths for the 
elastic members, and have exhibited excessive contact against adhesive 
coated surfaces of the elastic members. In addition, the conventional 
techniques have not adequately maintained desired separation spacings 
between individual elastic strands when the elastic member is composed of 
multiple strands of elastomeric material. 
BRIEF DESCRIPTION OF THE INVENTION 
The present invention provides a distinctive apparatus for applying an 
elastic member onto a substrate along a selected curvilinear location. The 
apparatus comprises transporting means for moving the substrate along the 
selected substrate path, and a rotatable nip roll for contacting the 
elastic member to place the elastic member onto the substrate along the 
curvilinear location. An elastic supplying means provides the elastic 
member, and a bonding means provides an adhesive in an arrangement which 
secures said elastic member to said substrate along said curvilinear 
location. The adhesive arrangement is configured to substantially avoid 
contact with said nip roll. A conveying means directs the elastic member 
along a selected elastic path, and a guiding means is positioned along the 
elastic path to deliver the elastic member across a free-span distance 
onto the nip roll while selectively changing a lateral positioning of the 
elastic member relative to a predetermined cross-direction. 
In another aspect of the invention, an apparatus for applying an elastic 
member onto a substrate along a selected curvilinear location comprises a 
transporting means for moving the substrate along a selected substrate 
path, and a rotatable nip roll for contacting the elastic member to place 
said elastic member onto the substrate along the curvilinear location. A 
guiding means delivers the elastic member across a free-span distance onto 
the nip roll while selectively changing a lateral positioning of said 
elastic member relative to a predetermined cross-direction. The guiding 
means includes a pivotable arm, and the arm is arranged to pivot about an 
axis which is aligned generally along the substrate path and generally 
perpendicular to a selected elastic path into the guiding means. A 
conveying means directs the elastic member along the selected elastic path 
into the guiding means, and an elastic supplying means provides the 
elastic member to the conveying means. 
A process aspect of the invention provides a method for applying an elastic 
member onto a substrate along a selected curvilinear location. The method 
comprises the step of moving the substrate along a selected substrate 
path, and contacting the elastic member with a rotatable nip roll which 
places the elastic member onto the substrate along the curvilinear 
location. An adhesive is provided in an arrangement which secures said 
elastic member to said substrate along said curvilinear location and which 
is configured to substantially avoid contact with said nip roll. The 
elastic member is guided across a free-span distance onto the nip roll 
while selectively changing a lateral positioning of the elastic member 
relative to a predetermined cross-direction. The elastic member is 
conveyed along a selected elastic path into the guiding step, and the 
elastic member is supplied into the conveying step. 
Another process aspect of the invention provides a method comprising the 
steps of moving said substrate along a selected substrate path, and 
contacting said elastic member with a rotatable nip roll which places said 
elastic member onto said substrate along said curvilinear location. The 
elastic member is secured to said substrate along the curvilinear 
location, and the elastic member is delivered across a free-span distance 
onto said nip roll while a lateral positioning of the elastic member is 
selectively changed relative to a predetermined cross-direction. The 
delivering is provided by moving said elastic member with a guide roller 
mounted on a pivotable arm, and pivoting the arm about an axis which is 
aligned generally along said substrate path and which is generally 
perpendicular to a selected elastic path onto the guide roller. The 
elastic member is conveyed along the selected elastic path into said 
guiding step, and the elastic member is supplied for movement into the 
conveying step. 
In particular aspects of the invention, the method and apparatus can be 
configured to apply a plurality of appointed elastic members onto selected 
side edge portions of the substrate. In other aspects of the invention, 
the guiding means can comprise a mechanism configured to more effectively 
place the elastic member across the desired curvilinear location in a 
periodic arrangement. 
The method and apparatus of the present invention can more reliably and 
efficiently place an elastic member in a selectively curved configuration 
across the surface of a substrate. The invention can avoid the use of 
complicated web paths that are more difficult to thread up and more 
difficult to maintain. Particular aspects of the invention can accommodate 
a variety of techniques for placing adhesive onto the elastic members, and 
can reduce undesired contact between construction adhesive and the 
transport mechanisms of the invention. Where the elastic member is 
composed of multiple, spaced apart elastic strands, the invention can be 
configured to more effectively maintain the desired spacings between the 
individual elastic strands.

DETAILED DESCRIPTION OF THE INVENTION 
The various embodiments of the invention will be described in the context 
of producing a disposable absorbent article, such as a disposable diaper. 
It is, however, readily apparent that the present invention may also be 
employed to produce other articles, such as covers, capes, gowns, pants, 
incontinence garments and the like. 
Disposable articles are typically intended for limited use, and are not 
intended to be laundered or otherwise cleaned for reuse. For example, a 
disposable diaper is discarded after it has become soiled by the wearer. 
With reference to FIG. 1, a representative disposable diaper article is 
shown in a fully-extended condition with all of its elasticized gathers 
removed. The garment article represented by disposable diaper 20 has a 
first waistband section 34, a second waistband section 36, and an 
intermediate section 38 which interconnects the waistband sections. The 
diaper comprises a backsheet layer 22, a liquid-permeable topsheet layer 
24 superposed in facing relation with the backsheet layer, and an 
absorbent body 26 interposed between the backsheet and topsheet layers. At 
least one fastening member 27, and preferably a complementary, opposing 
pair thereof, is connected to first waistband section 34 of diaper 20. In 
the illustrated embodiment, fastener 27 is composed of an adhesive tape 
fastener. Optionally, other types of fasteners, such as Velcro.RTM. type 
fasteners, snaps, hooks, and the like, may be employed. The fasteners are 
used to secure the diaper about the waist of the wearer. Further details 
of a representative diaper are described in U.S. patent application Ser. 
No. 757,760 entitled "Thin Absorbent Article Having Rapid Uptake of 
Liquid" filed Sep. 11, 1991 (Attorney Docket No. 9922), the disclosure of 
which is hereby incorporated by reference to the extent that it is 
consistent herewith. 
FIG. 2 generally shows a suitable mechanism for securing a stretched 
elastic member 42 onto a moving substrate web 44. For example, the 
material of substrate 44 may be employed to construct the backsheet 
component 22 of diaper 20. The stretched elastic applicating unit 46 
employs a system of tucker bars 74, which form a regularly spaced series 
of tuck regions 43 in substrate 44 to provide for an intermittent 
placement of stretched elastic segments along the length of the substrate. 
More particularly, the stretched elastic member is secured to the moving 
substrate web with discrete sections of the stretched elastic bridging 
across the gaps produced by the plurality of tuck regions 43 (FIG. 5). 
After the contacting sections of the elastic are attached to the substrate 
web, the bridging elastic sections are severed with a suitable cutting 
mechanism along appointed separation lines 47, and the web is then 
re-extended to operably remove tuck regions 43. Accordingly, the web area 
incorporated within the previously existing tuck regions will have no 
portions of elastic member 42 applied thereon. Only the previously 
untucked sections of web 44 will have sections of elastic member 42 
applied and secured thereto. As a result, substrate web 44 will have a 
selected intermittent placement of stretched, curved elastic segments at 
spaced apart positions along the length of the substrate (FIG. 5A). 
Suitable stretched elastic applicating units are described in U.S. Pat. No. 
4,227,952 issued Oct. 14, 1980, to Sabee and U.S. Pat. No. 4,498,944 
issued Feb. 12, 1985, to Krause et al., the disclosures of which are 
hereby incorporated by reference to the extent that they are consistent 
with the present description. 
In the present invention, it is contemplated that elastic member 42 may be 
either a unitary member composed of elastomeric material, or a composite 
member having a plurality of individual components. The individual 
components may all be composed of the same or different elastomeric 
materials. Alternatively, the composite may include a combination of 
elastomeric and non-elastomeric components. 
To apply a selectively curved elastic member onto to substrate 44, 
stretched elastic applicating unit 46 can advantageously incorporate a 
distinctive, curved elastic processing unit 48, such as illustrated in 
FIG. 3. Processing unit 48 provides an improved apparatus for applying an 
elastic member 42 onto a moving substrate 44 along a selected curvilinear 
location 50 (FIG. 5). The apparatus comprises a transporting means, such 
as a substrate conveyor 52, to move substrate 44 along a selected 
substrate path 54. A rotatable nip roll 56 contacts elastic member 42 to 
place the elastic member onto substrate 44 along the appointed curvilinear 
linear location 50. A guiding means, such as guide roller 58, delivers 
elastic member 42 across a free-span distance 60 onto an outer peripheral 
surface of nip roll 56 while selectively changing a lateral positioning of 
the elastic member relative to a predetermined cross direction 62 (FIG. 5) 
of the apparatus. Elastic conveying means, such as an upper peripheral 
surface portion of nip roll 56, directs elastic member 42 along a selected 
elastic path 66 into the guiding means. Elastic supplying means, such as a 
mechanism comprising transport roller 68, provides elastic member 42 to 
the conveying means. A bonding means, such as adhesive applicator 76, 
provides an adhesive in an arrangement which secures elastic member 42 to 
substrate 44 along curvilinear location 50. The adhesive arrangement is 
configured to substantially avoid contact with said nip roll. 
For the purposes of the present description, the various aspects of the 
invention will be described with respect to an individual processing unit 
48. It should be understood, however, that particular embodiments of the 
invention may comprise multiple processing units that are appropriately 
coordinated with one another to provide desired arrangements of multiple 
curved elastic members on a selected substrate. Each of the multiple 
processing units can be configured in accordance with the aspects of the 
invention described with respect to the individual processing unit 48. 
For example, when constructing a garment article, such as a disposable 
diaper, it may be desirable to apply a plurality of appointed elastic 
members onto each of the side edge portions of substrate 44. As 
illustrated in FIG. 4, the invention can readily be configured to define 
side edge regions 130 (FIG. 5) which substantially correspond to the side 
edges 45 of substrate 44. A designated processing unit 48 or 248 can be 
located in corresponding association with each of the side edge regions 
130 to provide a designated curved elastic member secured to substrate 44. 
Each processing unit includes a designated rotatable nip roll 56 or 256 
for contacting an appointed elastic member 42 or 242 to place the 
appointed elastic member onto substrate 44 along a designated curvilinear 
location 50 or 250 (FIG. 5). A designated guiding means, such as provided 
by a mechanism including guide roller 58 or 258, delivers the appointed 
elastic member across an appointed free-span distance 60 and directly onto 
the corresponding nip roll 56 or 256. Concurrently, the designated guiding 
means selectively changes a lateral positioning of the appointed elastic 
member relative to the cross direction 62 of the apparatus. A designated 
conveying means, such as provided by a conveying portion 118 of nip roll 
56 or a similar conveying portion of nip roll 256, directs the 
corresponding appointed elastic member along a selected elastic path onto 
its respective, corresponding guiding means. A designated elastic 
supplying means, such as one including transport roller 68 or 268, 
provides the appointed elastic members to their respective conveying 
means. A designated bonding means, such as adhesive applicator 76, is 
located in association with each of the side edge regions 130 to provide 
an adhesive in a designated arrangement which secures the appointed 
elastic member to substrate 44 along the designated curvilinear location. 
Each designated adhesive arrangement is configured to substantially avoid 
contact with its respectively associated nip roll. 
As representatively shown in FIG. 5, the curvilinear locations 50 and 250 
of the corresponding elastic members 42 and 242 are positioned at each of 
the two side edges 45 of substrate 44, and can be substantially 
symmetrically disposed relative to a longitudinal centerline 132 of 
substrate 44. The configuration of curvilinear location 50 is 
approximately a mirror image of the oppositely positioned curvilinear 
location 250. 
Referring again to FIG. 3, the illustrated embodiment of the invention has 
a transporting means for moving substrate 44 which includes a tuck drum 
70. The illustrated embodiment of the tuck drum includes a series of 
recess regions 72 which are substantially equally spaced along the 
circumferential peripheral surface of the tuck drum. The recess regions 
are constructed to accommodate the passage of tucker bars 74 employed to 
form tucks along the length of substrate 44. If the manufacturing process 
does not employ a tucker bar system, it is readily apparent that the 
recess regions could then be eliminated, and the peripheral surface of the 
drum 70 would be substantially continuous. 
Tuck drum 70 provides a complementary nipping roll which cooperates with 
nip roll 56 to form a nip region 120 therebetween. The nip region is 
employed to position and press elastic member 42 against a major facing 
surface of substrate 44 for securement along the preselected curved path. 
In the illustrated embodiment, an adhesive applicator deposits a selected 
pattern of adhesive, such as a hot melt pressure sensitive adhesive, onto 
elastic member 42, and the applied adhesive attaches the elastic member 
onto the surface of substrate 44. 
Tuck drum 70 is suitably mounted on a shaft to be rotatable about drum axis 
78. The drum is also operatively connected to the machine drive such that 
the peripheral, surface speed of tuck drum 70 substantially matches the 
speed at which substrate conveyor 52 is moving substrate 44 along machine 
direction 64 through the stretched elastic applicating unit 46 (FIG. 2). 
The illustrated embodiment of nip roll 56 rides along the peripheral 
surface of tuck drum 70, and is operably driven by a frictional engagement 
with respect to the peripheral surfaces of the tuck drum and nip roll. Nip 
roll 56 has a sufficiently large diameter to permit the nip roll to 
continuously traverse across recess regions 72 formed along the outer 
peripheral surface of tuck drum 70. The nip roll is able to bridge across 
recess regions 72 without disrupting the operation of the stretched 
elastic applicating unit. 
Nip roll 56 is rotatable about nip roll shaft 80, which is aligned along a 
cross direction 62 of the apparatus. The cross direction is perpendicular 
to machine direction 64 and generally parallel to substrate 44. Shaft 80 
is mounted on a support frame 82 which holds nip roll 56 in operable 
engagement with tuck drum 70 and substrate 44. The support frame includes 
support columns 92 and support arm assembly 86, and is constructed and 
arranged to resiliently urge nip roll 56 against tuck drum 70 with a 
selected level of engagement or nipping force. In addition, the 
construction of support frame 82 is able to selectively raise and lower 
nip roll 56 away and toward tuck drum 70 in a retraction and extension 
operation to facilitate maintenance. 
The shown embodiment of support arm assembly 86 includes a pair of support 
arms 88 which are positioned side by side in spaced-apart relation. The 
supporting ends of the support arms are positioned at a distal end of 
support arm assembly 86 and are configured to operably engage and hold 
opposite ends of nip roll shaft 80. The support arm assembly is rotatable 
about a support shaft 89, which is operably held by support cradle 90 to 
align and position the support shaft generally along cross direction 62 of 
the apparatus. Support cradle 90 includes a pair of upstanding support 
columns 92 which are suitably positioned astride substrate 44 and mounted 
in a substantially fixed position on a suitable support base. 
The downward, rotational movement of arm assembly 86 can be selectively 
controlled with an adjustable mechanical stop, such provided by a moveable 
jack screw. The mechanical stop can be adjusted to provide for a desired 
nip between the peripheral surfaces of nip roll 56 and tuck drum 70. 
In the illustrated embodiment, the desired levels of contact force between 
nip roll 56 and tuck drum 70 can, at least in part, be provided by the 
weight of nip roll 56 and support arms 88. In addition, the level of 
contact force between nip roll 56 and tuck drum 70 can be provided for by 
the operation of one or more pneumatic cylinders 84 connected to a first 
end of support arms 88. The actuation of pneumatic cylinder 84 can, for 
example, be configured to operably push or pull pivot support arms 88 
about support shaft 89 to help decrease or increase the desired contacting 
force between nip roll 56 and tuck drum 70. The portion of nipping force 
provided by pneumatic cylinder 84 can also be selectively disengaged, and 
a retracting mechanism 94 can be connected and operated to selectively 
rotate support arm assembly 86 about support shaft 89 to raise and lower 
nip roll 56 relative to tuck drum 70. The retracting operation can, for 
example, be useful for facilitating machine maintenance. 
A retracting mechanism may be mounted on a platform section of support 
cradle 90 and may employ a remotely positioned lever or cam-type mechanism 
to perform the desired retraction operation. Alternatively, the retracting 
mechanism may comprise a pneumatic actuator. For example, the shown 
embodiment of pneumatic cylinder 84 may be configured to selectively 
operate in a reverse-mode to push against arm assembly 86 to rotate arms 
88 about shaft 89 in a direction which operably raises nip roll 56 up and 
away from tuck drum 70. 
In the embodiment of the invention illustrated by FIG. 3, the guiding means 
delivers the elastic member across a free-span distance 60 directly onto 
nip roll 56. During the movement of elastic member 42 from the guiding 
means to nip roll 56, the elastic member has substantially no engagement 
with any intermediate components. While delivering the elastic member, the 
guiding means selectively changes a lateral, cross-directional positioning 
of elastic member 42. Accordingly, the position of the elastic member 
extends across a major surface of substrate 44 along a location pathway 
that curves toward and away from the longitudinal centerline 132 of 
substrate 44 in a predetermined pattern. 
The illustrated embodiment of the guiding means includes a rotatable guide 
roller 58 carried upon a pivotable arm 98. Guide roller 58 is rotatable 
about guide roller shaft 100 which is suitably mounted in a support 
bracket 102. Bracket 102 operably engages the end of guide shaft 100, and 
also connects to a first, distal end of pivotable arm 98. A second end of 
pivotable arm 98 is connected to rotatably pivot about pivot shaft 104. 
The pivot shaft has an axis of rotation which is aligned generally along 
substrate path 54, which extends generally along machine direction 64. In 
addition, the pivot axis of shaft 104 is aligned generally perpendicular 
to the elastic path 66 of elastic member 42 onto guide roller 58. While a 
perpendicular alignment can provide more optimum performance, it should be 
understood that some variation from an exact perpendicular can also 
provide acceptable performance. Such variation is preferably not more than 
about plus or minus (.+-.) 30 degrees, and more preferably is not more 
than about .+-.15 degrees. 
Particular aspects of the invention can include controlling means for 
selectively regulating the guiding means to change the lateral positioning 
of elastic member 42 in a predetermined pattern. In the illustrated 
embodiment, the controlling means is configured to continuously adjust the 
lateral positioning of elastic member 42 in a selected periodic pattern. 
In one aspect of the invention, the controlling means can include a cam 
mechanism for oscillating pivotable arm 98 about pivot shaft 104 through a 
predetermined periodic cycle pattern. Suitable cam mechanisms are 
available from CAMCO, a business having offices located at Wheeling, Ill. 
Vendors, such as CAMCO, are able to design and produce suitable cam 
mechanisms once they are advised of particular operational parameters. 
Pertinent parameters can include, for example, the dimensions and inertia 
of the moving components, the desired number of cycles per minute, and the 
particular trace pattern desired at the distal, first end of pivotable arm 
98. 
With reference to FIGS. 4 and 4A, cam box mechanism 106 is operably 
connected to coordinate with substrate conveyor 52 and the movement of 
substrate 44 along machine direction 64. In the illustrated embodiment, 
cam mechanism 106 is operably geared to tuck drum 70 through an 
appropriate system of properly sized pulleys, such as gear box pulley 108, 
and belts, such as gear box belt 110, to swing pivotable arm 98 through a 
desired cycling pattern which oscillates guide roller 58 along cross 
direction 62 to lay elastic member 42 onto substrate 44 along a desired 
curvilinear trace which substantially corresponds to the curvilinear 
location 50 of elastic member 42 across the surface of substrate 44. Gear 
box pulley 108 connects to a right angle gear box, such as a Model 66, 
Right Angle Bevel Gear box, available from Hub City Company, a business 
located in Aberdeen, S. Dak. As representatively shown in FIG. 4A, gear 
box 112 can be configured to operably drive one or more cam mechanisms 106 
through a drive system which includes pulleys 114 and engagement belt 116. 
The illustrated embodiment of the invention has a conveying means provided 
by a peripheral surface portion 118 of nip roll 56. The nip roll conveying 
portion 118, in the illustrated embodiment, is approximately one 
upper-quadrant section of the nip roll. Elastic member 42 is directed by 
conveying portion 118 along a selected elastic path 66 which is 
approximately perpendicular to both cross-direction 62 and 
machine-direction 64. 
It has been found that the placement location of elastic member 42 onto 
substrate 44 can more closely match the cross-directional positioning of 
guide roller 58 when the distance between guide roller shaft 100 and nip 
region 120 is kept to a minimum. Accordingly, when free-span distance 60 
is kept relatively small, the cross-directional positioning of elastic 
member 42 on substrate 44 can more closely match the cross-directional 
location and movement of guide roller 58 as it traverses through its 
pendulum arc carried on pivotable arm 98. If the free-span distance is too 
short, however, there may be an excessive tendency of elastic member 42 to 
twist over upon itself. Increasing the free-span distance 60 can reduce 
the fold-over forces exerted onto elastic member 42. Relatively larger 
free-span distances 60, however, can also reduce the correspondence 
between the cross-directional positioning of guide roller 58 and the 
cross-directional location of elastic member 42 on the substrate. 
In particular aspects of the invention, free-span distance 60 is not less 
than about 4 centimeters. Preferably the free-span distance is not less 
than about 6 cm, and more preferably is not less than 8 cm. In other 
aspects of the invention, free-span distance 60 is not more than about 14 
cm, preferably is not more than about 12 cm, and more preferably is not 
more than about 10 cm. Particular aspects of the invention can include a 
means for adjusting the free-span distance. The shown embodiment, for 
example, includes a pivotable arm which can be selectively positioned and 
locked in place at predetermined locations along the length dimension of 
shaft 104 to thereby adjust the length of free-span distance 60. 
In the illustrated embodiment, the effective length 96 of pivotable arm 98 
is about 15 centimeters, and the effective length is adjustable to 
accommodate different desired placements of elastic member 42. The 
effective length substantially corresponds to the distance of guide roller 
shaft 100 from the central axis of rotation of pivot shaft 104. It is 
readily apparent that the length of pivot arm 98 and the angle through 
which the pivot arm is swung can effectively control the cross-directional 
distance traversed by guide roller 58 along the cross direction 62 of the 
apparatus. The longer the length of pivotable arm 98 and/or the greater 
the angle of oscillation 99 (FIG. 4) imparted to pivotable arm 98, the 
larger the distance traversed by guide roller 58 during each cycle of cam 
mechanism 106. Similarly, a smaller length of pivotable arm 98 and/or a 
smaller angle of oscillation 99 will traverse guide roller 58 through a 
relatively smaller cross-directional distance during each cycle of the 
guiding means. In the shown embodiment, the effective length of pivotable 
arm 98 can be adjusted by moving bracket 102 along the pivotable arm and 
securing it at the desired length location with a suitable locking 
mechanism, such as a locking screw clamp. 
The angle of oscillation 99 employed in the shown embodiment can be about 
23.5 degrees to produce a particular, desired curvilinear location of 
elastic member 42 onto substrate 44. The resultant location is configured 
in a periodically undulating pattern wherein the elastic member is 
positioned along a curved path which varies through a side-to-side, 
traversing distance of approximately 0.75-1.5 inch measured along cross 
direction 62. 
To afford particular advantages, pivotable arm 98 can be configured to have 
a rotational oscillation along a plane which is generally aligned with 
cross direction 62 and generally perpendicular to machine direction 64. 
With this arrangement, the invention can, for example, generate a smaller 
change in the length of the path of elastic member 42 between nip region 
120 and the point at which the elastic member departs from the conveying 
portion 118 of the nip roll. In addition, such an arrangement can 
facilitate the making of very small, incremental adjustments of the 
distance between roller 58 and nip region 120. 
The elastic supplying means for providing elastic member 42 onto the 
conveying portion of nip roll 56 can include a delivery assembly 122. The 
shown delivery assembly includes a supporting bracket 124, which connects 
to support arm assembly 86. Bracket 124 rotatably supports a transport 
roller 68 which operably directs stretched, elastomeric material 41 onto 
the conveying portion 118 of nip roll 56. In particular embodiments of the 
invention, the elastomeric material can comprise a single, substantially 
unitary ribbon of stretched elastomer. In the illustrated embodiment, the 
stretched elastic material comprises a plurality of elastic strands, such 
as three or four individual strands of Lycra.RTM. elastomer. With this 
embodiment, the outer cylindrical surface of transport roller 68 can 
include a plurality of spaced-apart grooves each of which is configured to 
accept therein an individual strand of elastic. The grooves are configured 
to provide a desired spaced-apart distance between the individual elastic 
strands. For example, the illustrated embodiment includes four individual 
elastic strands with adjacent strands spaced apart by a distance of about 
0.32 centimeters. 
In a particular aspect of the invention, elastic member 42 comprises a 
composite member composed of multiple, stretched elastic strands secured 
to a ribbon of carrier sheet material 128. In the illustrated embodiment, 
for example, carrier sheet 128 may be composed of a polypropylene ribbon 
having a cross-directional width dimension of about 1.9 centimeters. 
Carrier sheet 128 is delivered from a suitable supply roll (not shown) 
employing conventional web supplying techniques well known in the art such 
as supplying mechanism 129. The carrier sheet can help to maintain desired 
spaced positionings between individual elastic strands. In addition, the 
carrier sheet can operably cover any assembly adhesive that has been 
employed to attach the elastic strands onto substrate 44. Such a 
configuration can help isolate the adhesive, and help prevent undesired 
contact between the adhesive and other components of the manufacturing 
apparatus, such as nip roll 56. 
Desired levels of tension and stretch are applied to elastic member 42 
prior to delivery onto transport roller 68 and prior to securement onto 
the carrier sheet. The stretch and tension can be applied using 
conventional techniques well known in the art. For example, the elastic 
strands comprising elastic member 42 can be stretched about 200-400 
percent employing a conventional system of differential traction rolls 
operated at different rotational speeds. 
Various techniques may be employed to secure elastic member 42 onto 
substrate 44. For example, a desired attachment may be provided by 
adhesive bonding, thermal bonding, ultrasonic bonding or the like. In the 
representatively shown embodiment, elastic member 42 is adhered to 
substrate 44 with a hot melt, pressure sensitive adhesive, such as a H2096 
adhesive available from Findley Adhesives Company, a business having 
offices at Wauwatosa, Wis. The selected hot melt adhesive is deposited 
onto elastic member 42 by adhesive applicator 76. The illustrated 
embodiment of applicator 76 deposits a swirl pattern of overlapping loops 
of hot melt adhesive onto the elastic member. In particular, the adhesive 
is applied onto portions of the elastic member that are in contact with or 
in a close, spaced-adjacent position relative to the conveying portion 118 
of nip roll 56. Examples of conventional devices that can be adapted to 
apply such swirled patterns of hot melt adhesive are described in U.S. 
Pat. No. 4,031,854 to Sprague Jr. and U.S. Pat. No. 3,911,173 to Sprague 
Jr. and U.S. Pat. No. 4,785,996 to Ziecker et al. In the illustrated 
embodiment, adhesive applicator 76 includes adhesive nozzles manufactured 
by J&M Laboratories, a business having offices at Dawsonville, Ga. 
A particular, alternative aspect of the invention illustrated in FIG. 6 can 
have a guiding means which includes a supplemental guide mechanism, such 
as provided by supplemental guide roller 134 and its associated supporting 
bracket 136. Supplemental guide roller 134 is rotatable about an 
associated shaft 138, which in the illustrated embodiment is aligned 
substantially parallel to shaft 100 of the primary guide roller 58. 
Mounting bracket 136 operably supports and holds shaft 138, and connects 
to pivotable arm 98. In a particular aspect of the invention, mounting 
bracket 136 is constructed to selectively position shaft 138 such that the 
upper, horizontal tangent line to guide roller 134 is in substantial 
alignment with the longitudinal axis of rotation of pivot shaft 104. As a 
result, the rotational movement of pivotable arm 98 about pivot shaft 104 
can generate a twisting motion to supplemental guide roller 134 which 
selectively cants the axis of shaft 138 relative to the conveying portion 
118 of nip roll 56. Elastic member 42 is threaded over supplemental guide 
roller 134 and contacts the peripheral surface thereof. When supplemental 
guide roller 134 twists about the axis of rotation of pivot shaft 104, the 
contacting surface of supplemental guide roller can impart an oscillating, 
substantially pure twisting action to elastic member 42. As a result, 
supplemental roller 134 can more effectively change the direction of 
movement of elastic member 42 and direct it toward guide roller 58 while 
generating lower side forces against the elastic member. The reduced 
levels of side force can advantageously reduce the tendency of the elastic 
member to fold over upon itself while the oscillating movement of guide 
roller 58 is operating to change the lateral positioning of the elastic 
member along the desired curvilinear location which traverses across the 
surface of substrate 44. 
The illustrated embodiment of applicator nip roll 56 is an approximately 
20.3 centimeter diameter, cylindrical roll having an axial width of about 
8.6 centimeters and having an outer surface composed of silicone rubber. 
Tuck drum 70 is an approximately 40 centimeter diameter, cylindrical roll 
having an axial width dimension of about 38 centimeters. Recess regions 72 
can, for example, extend radially into the tuck drum for a distance of 
about 11 centimeters. It is readily apparent that the circumferential 
length and radial depth of recess regions 72 can be modified to suitably 
accommodate the placement of tucker bars therein during the operation of 
the apparatus. Where the apparatus is configured to not include the tucker 
bar mechanisms, the recess regions may be eliminated from drum 70. 
Accordingly, the peripheral cylindrical surface of drum 70 would then be 
substantially continuous. For example, U.S. Pat. No. 4,711,683 issued Dec. 
8, 1987 to Merkatoris describes an alternative technique for applying 
stretched elastics onto a moving substrate without employing a tucker bar 
system. 
A further aspect of the invention may include a transporting means which 
includes a supplemental transport mechanism, such as a separate applicator 
roll. As representatively shown in FIG. 7, for example, applicator roll 
140 provides a transport mechanism which is separate and spaced away from 
nip roll 56. As a result, the constructions of nip roll 56 and applicator 
roll 140 can be individually tailored to meet different processing 
parameters. For example, it may be desireable to selectively heat or chill 
applicator roll 140 to better accommodate the process of applying adhesive 
onto elastic member 42. Alternatively, the applicator roll may be 
separately adapted and configured to provide a complementary component of 
a sonic bonding or thermal bonding operation. 
In alternative configurations of the invention, such as representatively 
shown in FIG. 8, the guiding means can comprise a guide roller mounted on 
a pivotable arm 150 with the pivotable arm arranged to pivot about an axis 
152 which is aligned generally perpendicular to substrate path 54. In 
addition, the axis may be aligned generally along elastic path 66 into the 
guiding means. For example, the longitudinal axis of pivot shaft 152 can 
be aligned generally perpendicular to substrate path 54. As a result, 
pivotable arm 150 can be configured to rotationally oscillate about the 
pivot shaft along a plane of oscillation which is generally parallel to 
substrate 44. 
In yet another alternative aspect of the invention, the guiding means can 
be configured with a guide roller 58 which oscillates along a 
substantially linear path directed along cross direction 62, as 
representatively shown in FIGS. 9 and 9A. For example, a suitable ball nut 
mechanism, ball screw mechanism or barrel cam mechanism 154 may be 
employed to linearly oscillate guide roller 58 along shaft 156. The rate 
and magnitude of the oscillation can be selectively regulated by 
conventional means. 
Having thus described the invention in rather full detail, it is readily 
apparent that various changes and modifications can be made without 
departing from the spirit of the invention. All of such changes and 
modifications are contemplated as being within the scope of the present 
invention, as defined by the subjoined claims.