The field of the present invention relates generally to apparatus and methods for folding products and more particularly, to apparatus and methods for folding products with increased alignment control at relatively high line speeds.
One known technology used to fold products as they proceed through a product manufacturing system is “blade folding”. Blade folding involves striking a discrete, moving product at a desired location with a blade to form a “bite” in the product. The bite is directed into a set of in-running conveyor belts to fold portions of the product. Examples of such blade folding apparatus and methods of their use are described in U.S. Pat. No. 4,053,150 to Lane; U.S. Pat. No. 4,519,596 to Johnson et al.; and U.S. Pat. No. 4,650,173 to Johnson et al. Various products can be folded using blade folding apparatus including disposable personal care products. Disposable personal care products are well known and include diapers, training pants, adult incontinence garments, feminine pads, bed liners, pet-care mats, dinner napkins, toweling, chair liners, etc.
One disadvantage of known blade folding technology is that the precision and repeatability of the folds in the products is dependent upon the timing of when the blade strikes the moving product as well as the traction of the in-running belts to the product bite. Plus, blade folding requires that the product is “free” when it is struck by the blade. Thus, there is a period of time in the folding process when a leading portion of the product is not held in place, and as a result, is not under direct positioning control. These features of blade folding are undesirable when precise fold positioning is needed, particularly at high speeds, such as speeds ranging from 400 products per minute to 4000 products per minute, depending on the product being folded.
Another disadvantage of blade folding is the “cudgeling effect”. That is, the bludgeoning force of the blade striking the product can result in deformed products, damaged products, poor folding alignment, poor folding repeatability, as well as other undesirable results.
Thus, there is a need for a folding apparatus and method of folding products at high speeds where the products can be folded in repeatable alignment at high speeds. There is a further need for apparatus and methods for folding products without the resulting deformation, damage and/or other undesirable effects inherent in current blade folding apparatus and methods.
In one aspect, an apparatus for folding products generally comprises a conveying member adapted to convey the product, an oscillating member disposed adjacent the conveying member, and a folding roll disposed adjacent the conveying member and the oscillating member. The oscillating member is adapted to grasp and lift a first portion of the product from the conveying member while the product is being conveyed by the conveying member. The oscillating member is moveable in a first direction away from the conveying member and in a second direction toward the conveying member. The folding roll is adapted to receive the first portion of the product from the oscillating member and to place the first portion of the product into engagement with a second portion of the product such that the product is in a folded configuration.
In another aspect, a method of folding a product generally comprises directing the product along a conveying member at a conveying speed. The product has a first portion, a second portion, and a fold axis separating the first portion and the second portion. The first portion of the product is lifted from the conveying member with an oscillating member while the product is being conveyed by the conveying member and the oscillating member is rotating in a first rotational direction. The first portion of the product is transferred to a folding roll rotating in the first rotational direction. The first portion of the product is transferred from the folding roll to the conveying member such that the first portion of the product is in overlying relationship with the second portion and the product is folded generally along the fold axis.
Corresponding reference characters indicate corresponding parts throughout the drawings.
For exemplary purposes only, the illustrated folding system 50 and thus, the folding apparatus 100 will be described herein as a disposable training pant folding system and folding apparatus. It is understood, however, that the folding system 50 can be configured to fold numerous other products, including but not limited to, other types of personal care products, foil products, film products, woven products, packaging products, industrial products, food products, etc., whether disposable or non-disposable, and whether absorbent or non-absorbent, without departing from the scope of the invention. Other suitable personal care products that could be folded by the system 50 include, but are not limited to, diapers, adult incontinence garments, panty liners, and feminine pads.
As illustrated in
As illustrated in
With reference to now to
It is understood that the puck 164 can be flush with the remainder of the outer cylinder 152 of the oscillating member 150 (i.e., not raised). It is further understood that the apertures 169 in the puck 164 of the outer cylinder 152 can be arranged differently, that there could be more or fewer apertures than illustrated in the accompanying drawings, and that the apertures can have different shapes and sizes than those illustrated. It is also understood that the inner and outer cylinders could be other shapes that provide concentric surfaces such as partial spheres, cones, a stepped series of cylinders, or partials of the above since the oscillating member does not need to rotate 360 degrees.
In the illustrated embodiment, the inner cylinder 151 does not rotate and defines an interior chamber 153 (
A pair of end plates 154 is disposed adjacent the ends of the inner cylinder 151 and closes the interior chamber 153 (
A drive assembly 157 is operatively connected to the outer cylinder 152 for rotating the outer cylinder with respect to the inner cylinder 151. The drive assembly 157 includes a hub 158, a shaft 159 coupled to the hub and a suitable drive mechanism (not shown) capable of rotating the shaft and the hub. In the illustrated embodiment, the drive assembly 157 is variable and is capable of rotating the outer cylinder 152 at variable speeds and in both a clockwise direction and a counterclockwise direction.
With reference now to
As a result, the oscillating member 150 has a first vacuum profile with the inner cylinder 151 in the first position, and a second vacuum profile with the inner cylinder in the second position. That is, the vacuum is turned on and off at different points by the oscillating member 150 when the inner cylinder is in the first position as compared to when the inner cylinder is in the second position.
In the illustrated embodiment, the actuator 168 comprises a voice coil motor (
As illustrated in
In the illustrated embodiment, the inner cylinder 171 is stationary and defines an interior chamber 173 (
A pair of end plates 174 are disposed adjacent the ends of the inner cylinder 171 and closes the interior chamber 173 (
A drive assembly 176 is operatively connected to the outer cylinder 172 for rotating the outer cylinder with respect to the inner cylinder 171. The drive assembly 176 includes a hub 177, a shaft 178 coupled to the hub, and a suitable drive mechanism (not shown) capable of rotating the shaft and hub. In the illustrate embodiment, the drive assembly 176 is capable of rotating the outer cylinder 172 relative to the inner cylinder 171 at variable speeds in a counterclockwise direction. It is understood, however, that the drive assembly 176 can be configured to rotate the outer cylinder 172 in a clockwise direction or in both the counterclockwise and clockwise directions.
Both the oscillating member 150 and the folding roll 170 are described herein as using vacuum to hold the training pant 500 to their respective outer cylinder 152, 172. Thus, both of the illustrated oscillating member 150 and the folding roll 170 can broadly be referred to as a vacuum roll. It is contemplated, however, that other suitable structure (e.g., adhesive, frictional members, nano-fabricated hairs) capable of grasping, controlling, and releasing the training pant 500 can be used instead.
With reference again to
As mentioned above, the folding system 50 schematically illustrated in
As seen in
The illustrated training pant 500 also includes an outer cover 540, and a liner 542 joined to the outer cover, and an absorbent core 544 disposed between the outer cover and the liner. A pair of containment flaps 546 is secured to the liner 542 and/or the absorbent core 544 for inhibiting generally lateral flow of body exudates. The outer cover 540, the liner 542 and the absorbent core 544 can be made from many different materials known to those skilled in the art. The illustrated training pant 500 further includes a pair of transversely opposed front side panels 534, and a pair of transversely opposed back side panels 535. The side panels 534, 535 can be integrally formed with either the outer cover 540 or the liner 542, or may comprise separate elements.
As seen in
The fastening components 582, 584 can comprise any refastenable fasteners suitable for absorbent articles, such as adhesive fasteners, cohesive fasteners, mechanical fasteners, or the like. In one particular embodiment, the fastening components 582, 584 comprise complementary mechanical fastening elements. Suitable mechanical fastening elements can be provided by interlocking geometric shaped materials, such as hooks, loops, bulbs, mushrooms, arrowheads, balls on stems, male and female mating components, buckles, snaps, or the like.
In the illustrated embodiment, the first fastening components 582 comprise loop fasteners and the second fastening components 584 comprise complementary hook fasteners. Alternatively, the first fastening components 582 may comprise hook fasteners and the second fastening components 584 may comprise complementary loop fasteners. In another embodiment, the fastening components 582, 584 can comprise interlocking similar surface fasteners, or adhesive and cohesive fastening elements such as an adhesive fastener and an adhesive-receptive landing zone or the like. Although the training pant 500 illustrated in
The illustrated training pant 500 further includes a front waist elastic member 554, a rear waist elastic member 556, and leg elastic members 558, as are known to those skilled in the art. The front and rear waist elastic members 554, 556 can be joined to the outer cover 540 and/or liner 542 adjacent the leading edge 527 and the trailing edge 529, respectively, and can extend the full length of or part of the length of the edges. The leg elastic members 558 can be joined to the outer cover 540 and/or liner 542 along transversely opposing leg opening side edges 536 and positioned in the crotch region 526 of the training pant 500.
The elastic members 554, 556, 558 can be formed of any suitable elastic material. As is well known to those skilled in the art, suitable elastic materials include sheets, strands or ribbons of natural rubber, synthetic rubber, or thermoplastic elastomeric polymers. The elastic materials can be stretched and bonded to a substrate, bonded to a gathered substrate, or bonded to a substrate and then elasticized or shrunk, for example with the application of heat, such that elastic constrictive forces are imparted to the substrate. One non-limiting example of a suitable elastic material includes dry-spun coalesced multifilament spandex elastomeric threads sold under the trade name LYCRA, available from Invista, having a place of business located in Wichita, Kans., U.S.A.
In this embodiment and as illustrated in
The training pant 500 is illustrated in
In the illustrated embodiment, half of the training pants 500 are delivered to each of the oscillating members 150. Since both of the folding apparatus 100 are the same, the operation of only one of them will be described herein. The training pant 500 is delivered to the oscillating member 150 by the conveying member 80 with its outer cover 540 facing downward (i.e., toward the conveying member) and its first and second fastening components 582, 584 facing upward (i.e., away from the conveying member). The oscillating member 150 is aligned with the conveying member 80 such that the narrower portion of slots 163 (the portions of the slots having the narrower width W2) in the inner cylinder 151 of the oscillating member begins at approximately the tangent point with the conveying member.
When the leading edge 527 of the first portion 571 of the training pant 500 reaches the oscillating member 150, the liner 542 of the training pants is aligned with and grasped by the puck 164 of the outer cylinder 152 of the oscillating member (
As seen in
In the illustrated embodiment, the engagement surface 107 of the bump roll 105 and the puck 164 of the oscillating member 150 have approximately the same size. As a result, the bump roll 105 is in contact with the conveying member 80 throughout the transfer of the first portion 571 of the training pant 500 from the conveying member to the puck 164 of the oscillating member 150. It is understood, however, that engagement surface 107 of the bump roll 105 can be larger or smaller than the puck 164 of the oscillating member 150.
As the bump roll 105 continues to rotate, the engagement surface 107 moves out of contact with the lower surface of the conveying member 80 (
With reference still to
The first portion 571 of the training pant 500 is transferred to the puck 164 of the outer cylinder 152 of the oscillating member 150 while the outer cylinder (and thereby the puck) is being rotated relative to the conveying member 80 by the drive assembly 157 of the oscillating member. As seen in
Once the first portion 571 of the training pant 500 is transferred from the conveying member 80 to the oscillating member 150 (or shortly thereafter), the outer cylinder 152 of the oscillating member begins to slow down. That is, the drive assembly 157 of the oscillating member 150, which is variable, reduces the surface speed at which the outer cylinder 152 of the oscillating member rotates relative to the conveying member 80. Once the outer cylinder 152 of the oscillating member 150 rotates a predetermined amount in the counterclockwise direction, the outer cylinder stops and rotates in the opposite direction (i.e., the clockwise direction and broadly, a “second direction”). In the illustrated embodiment, the outer cylinder 152 of the oscillating member 150 moves in a generally pendular manner through about 270 degrees. In other words, the outer cylinder 152 of the oscillating member 150 rotates in a counterclockwise direction through about three-fourths of a rotation, stops, and then rotates back in a clockwise direction to its original position.
Because of the slowing, stopping, and change in rotational direction of the outer cylinder 152 of the oscillating member 150 relative to the conveying member 80, which is moving at a constant surface speed, the training pant 500 begin to fold (
With the outer cylinder 152 of the oscillating member 150 stopped (
As the outer cylinder 152 of the oscillating member 150 rotates in the clockwise direction (
As mentioned above, the outer cylinder 152 of the oscillating member 150 rotates in a counterclockwise direction through about three-fourths of a rotation, stops, and then rotates back in a clockwise direction to its original position. The actuator 168 of the illustrated embodiment is configured to be in its normal position when the outer cylinder 152 is rotating in the counterclockwise direction, and in its actuated position when the outer cylinder is rotating in its clockwise direction. As a result, the inner cylinder 151 is in the first position when the outer cylinder 152 is rotating counterclockwise and the second position when the outer cylinder is rotating in the clockwise direction. It is understood that the position of the inner cylinder 151 can be changed (i.e., the actuator 168 actuated or de-actuated) when the outer cylinder 152 is at a stopped position or while it is rotating.
With the outer cylinder 152 of the oscillating member 150 rotating in the clockwise direction, the first portion 571 of the training pant 500 is contacted by the puck 186 of the outer cylinder 172 of the folding roll 170 at a second nip defined by the oscillating member and the folding roll (
Because the vacuum being applied by the oscillating member 150 to the first fastening components 582 and front waist elastic member 554 of the training pant 500 is blocked by the inner cylinder 151, the first portion 571 of the training pant transfers from the puck 164 of the oscillating member to the puck 186 of the outer cylinder 172 of the folding roll 170 (
Once the first portion 571 of the training pant 500 is transferred from the oscillating member 150 to the folding roll 170, the rotational surface speed of the outer cylinder 172 of the folding roll 170 is increased by its drive assembly 176 to generally match the rotational surface speed of the conveying member 80.
The first portion 571 of the training pant 500 is brought into engagement with the conveying member 80 at a third nip defined between the folding roll 170 and the conveying member such that the first portion 571 of the training pant is in overlying relationship with the second portion 572 (
The primary and secondary openings 180, 182 in the inner cylinder 171 of folding roll 170 terminate adjacent the third nip. As a result, the vacuum holding the first portion 571 of the training pant 500 to the puck 186 of the folding roll 170 is blocked from contact therewith. As a result, the first portion 571 of the training pant 500 is transferred back to the conveying member 80 and the training pant is arranged in its folded configuration. In addition, the relative movement between the folding roll 170 and conveying member 80 applies both a compressive force and a shear force to the first and second fastening components 582, 584 thereby securely engaging the first and second fastening components together.
The training pant 500, which is in its folded configuration and has its first and second fastening components 582, 584 engaged, is then transferred by the conveying member 80 away from the other components of the folding apparatus 100.
In one suitable embodiment, training pants 500 can be folded at high line speeds (i.e., rates of 400 products per minute (ppm) or greater, such as 400 ppm to 4000 ppm, or 600 ppm to 3000 ppm, or 900 ppm to 1500 ppm). In the embodiment illustrated in
Table 1, provided below, provides examples of potential sizes and velocities suitable for the oscillating member 150 and the folding roll 170 of the folding apparatus 100. More specifically, Table 1 provides three suitable radii and velocities for the oscillating member 150 and the folding roll 170 of the folding apparatus 100. In addition, Table 1 provides suitable lengths for the puck 164 of the oscillating member 150.
Equations for calculating suitable relative positions of the oscillating roll 150 and folding roll 170 are provided below and illustrated in
Given R2 and R3, the center angles α,β can be computed using the following equations. See
The horizontal center distance Ct (
Ct=√{square root over ((R2+R3)2−(R3−R2)2)}{square root over ((R2+R3)2−(R3−R2)2)} (3)
As seen in
The folding roll circumference (the folding roll makes one revolution every N products and h=Vp/Vf):
The leading end of the product reaches the folding roll at the 6 O'clock position at same time as the trailing end of the product:
The puck of the oscillating member does not dwell at zero speed
b
4
=b
5 (6)
Conveyor traverses product length and center distance from fold start to fold complete:
Puck sweep CW equals puck sweep CCW:
−b1+b2+b4+b5+b6−b8−b9−b11=0 (8)
Puck dwells at VP for length of puck
Puck travels past tangency by over travel angle:
No discontinuity in Puck slope b5 to b6:
(1−h)b5−b6+h b10=0 (11)
Final puck slope equals initial puck slope:
b
1
+b
8
−b
9
−b
11=0 (12)
Begin puck motion: Freely choose b11:
b
11
=y (13)
Puck Reaches Conveyor Velocity: Freely choose b1:
b
1
=z (14)
Puck Forward Sweep: Puck sweeps through included angle γ plus arc equal to puck length:
Puck Matches Conveyor: Puck dwells with conveyor roll for arc equal to puck length:
Puck Begins Accelerating: Freely choose b10:
b
10
=y (20)
In one suitable embodiment, the puck 164 of the oscillating member 150 and the folding roll 170 surfaces are moving at the same speed when they meet at the tangency point. There are not enough degrees of freedom to allow constraining the puck to reach velocity V, in a sweep angle equal to γover. However, one is free to choose γover until the difference between the area under the velocity curve from b5 to b10 equals the puck radius times γover. See
Putting the equations of constraint into matrix form we have:
The solution for the bi's in the above set of equations can be found using either Gaussian elimination or matrix inversion. The solution using matrix inversion is of the form:
B=A
−1
·C
Consider a folder with the following parameters:
The above parameters yield the following center angles:
Oscillating member and folding roll puck angles:
The timing solution in the above system is as follows:
Other apparatus suitable for holding, controlling, transferring, folding, winding and/or otherwise handling flexible materials and articles (including training pants) are described in U.S. patent application Ser. No. 12/972,012 entitled FOLDING APPARATUS AND METHOD OF FOLDING A PRODUCT (attorney docket no. 27839-3533, K-C 64535936US01); U.S. patent application Ser. No. 12/972,037 entitled FOLDING APPARATUS HAVING ROLLS WITH VARIABLE SURFACE SPEEDS AND A METHOD OF FOLDING A PRODUCT (attorney docket no. 27839-3535, K-C 64535590US01); and U.S. patent application Ser. No. 12/972,082 entitled VACUUM ROLL AND METHOD OF USE (attorney docket no. 27839-3537, K-C 64536049US01). Each of these applications is incorporated herein by reference in their entireties.
When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
As various changes could be made in the above without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
This application is a divisional application of U.S. patent application Ser. No. 12/971,999 entitled Folding Apparatus and Method of Folding a Product, filed Dec. 17, 2010, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
Parent | 12971999 | Dec 2010 | US |
Child | 14089026 | US |