Apparatus and method for folding

Abstract

Discrete items are conveyed, preferably by a vacuum conveyor, in a machine direction toward a pair of rotating blades. A first intended target of folding, for instance a right portion of front and back panels of a diaper, travels up a ramp, raising the level of the intended target. A rotating blade passes under the intended target of folding, and folds the right portion of front and back panels of a diaper over. If desired, a second intended target of folding, for instance a left portion of front and back panels of a diaper, travels up a second ramp, raising the level of the intended target. A rotating blade passes under the second intended target of folding, and folds the left portion of front and back panels of a diaper over. The folded diaper then exits the folding system and travels downstream for further processing as desired.

Claims

1. An apparatus for folding an article, the apparatus comprising: a conveying surface at a first elevation and along a machine direction, to receive at least a midsection of the article; a first blade above the conveying surface; and a first ramp to receive a first panel of the article, the first ramp having a conveyor level section adjacent the conveying surface at the first elevation, a blade clearance level section at a second elevation above the first blade, and a sloped midsection connecting the conveyor level section with the blade clearance level section, wherein the first blade passes underneath the blade clearance level section and above the conveying surface to create a first fold in the article by folding over at least a portion of the first panel along a first fold line onto the midsection, and wherein the sloped midsection is not parallel with the blade clearance level section.

2. The apparatus of claim 1, wherein the first fold line is parallel with the machine direction.

3. The apparatus of claim 1 further comprising: a second blade above the conveying surface; and a second ramp to receive a second panel of the article, the second ramp having a conveyor level section adjacent the conveying surface at the first elevation, a blade clearance level section at a third elevation above the second blade, and a sloped midsection connecting the conveyor level section with the blade clearance level section; wherein the second blade passes underneath the blade clearance level section of the second ramp and above the conveying surface in order to create a second fold in the article by folding over at least a portion of the second panel along a second fold line onto the midsection.

4. The apparatus of claim 3 wherein the second blade folds over at least a portion of the second panel onto the first panel.

5. The apparatus of claim 3 wherein the second blade comprises a first zone having a first coefficient of friction and a second zone having a second coefficient of friction different than the first coefficient of friction.

6. The apparatus of claim 3 wherein the first and second blades have different coefficients of friction.

7. The apparatus of claim 3 wherein the second blade passes over the first panel and the midsection of the article, and wherein the second blade passes under the second panel of the article and the blade clearance level section of the second ramp to create the second fold.

8. The apparatus of claim 1 wherein the first blade comprises a first rotating blade which rotates independently above the conveying surface and which rotates into contact with at least a portion of the first panel.

9. The apparatus of claim 1 wherein the second blade comprises a second rotating blade which rotates independently above the conveying surface and which rotates into contact with at least a portion of the second panel.

10. The apparatus of claim 1 wherein the first blade comprises a first zone having a first coefficient of friction and a second zone having a second coefficient of friction different than the first coefficient of friction.

11. The apparatus of claim 1 wherein the first blade passes over the midsection of the article, and wherein the first blade passes under the first panel of the article and the blade clearance level section of the first ramp to create the first fold.

12. The apparatus of claim 1 wherein the conveying surface moves independently from the first ramp.

13. The apparatus of claim 1 further comprising a tucker bar positioned above the conveying surface and downstream of the first ramp, wherein the tucker bar maintains the first fold as the article is carried along by the conveying surface.

14. The apparatus of claim 1 wherein a shape of the first blade comprises one of an oblong ear shape, a circular shape, and a bow-tie shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a top view of a representative web folding system, showing a single diaper product riding on a conveyor toward a pair of folding blades;

(2) FIG. 2 is a side view of a folding system of the present invention;

(3) FIG. 3 is a top view of a representative web folding system, showing a single diaper product riding on a conveyor toward a pair of folding blades, with a right panel portion of the diaper riding up a ramp and approaching a rotating blade;

(4) FIG. 4 is a top view of the right panel portion of the diaper being folded by a rotating blade;

(5) FIGS. 5 and 6 are top views of a representative web folding system, showing a folded over right panel portion, and showing a left panel portion of the diaper riding up a second ramp and approaching a second rotating blade;

(6) FIGS. 7 and 8 are top views of the left panel portion of the diaper being folded by a rotating blade;

(7) FIG. 9 is top view of the folded diaper exiting the folding system and being passed downstream for further processing;

(8) FIG. 10 is a top view of an alternate embodiment of the folding system shown in FIG. 1, the alternate embodiment including a tucker bar to maintain the first fold, and a tucker roller to maintain the first and second folds intact during downstream passage;

(9) FIG. 11 is a side view of the folding system shown in FIG. 10;

(10) FIGS. 12a-c are top views of alternate blade configurations.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(11) Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

(12) IL is noted that the present folding techniques and apparatus are described herein with respect to products such as diapers, but as previously mentioned, can be applied to a wide variety of processes in which components are required to be folded. The present methods can be used to fold a portion of a web, or discrete portions, as desired. The same apparatus and techniques can be used for ears, panels, hook materials, or any other situation in which folding is desired.

(13) Importantly, the methods taught in the present application are applicable not only to diapers and the like, but in any web based operation. The folding techniques taught herein can be directed any component of a manufactured article desired to be folded, i.e., the methods taught herein are not product specific. For instance, the present methods can be applied as easily with respect to diaper components as they can for feminine hygiene products.

(14) Referring now to FIG. 1, a top view of a representative web folding system is shown. A diaper product 10 riding on a conveyor 18, preferably a vacuum conveyor with vacuum commutation ports 18a, is conveyed toward a pair of folding blades 22.

(15) Vacuum conveyor ports 18a can extend the entire length of vacuum conveyor 18, or extend for selected portions of conveyor 18, such as shown, or extend for an entire product length. In pant-type diapers, typically an absorbent core section 16 is contained in a midsection of diaper 10. Left side of panel 12 consists of both the front and rear left portions of panels of a previously formed diaper 10. Right side of panel 14 consists of both the front and rear left portions of panels of a previously formed diaper 10. Intended fold lines L for the left panel 12 and R for the right panel 14 are acted upon by the system.

(16) The first intended target of the folding, fold line R for the right panel 14 is seen traveling onto ramp 20, the ramp 20 comprising three sections, a conveyor level 20a, a sloped midsection 20b, and a blade clearance level 20c. Two ramps 20 are provided, one for each of the intended fold lines L for the left panel 12 and R for the right panel 14.

(17) Blade 22, with blade lobes 22a and 22b, is driven in the direction shown by rotor 24. Preferably, two independent, servo controlled blades 22 are programmed to aid in actively folding each part of the product 10.

(18) Conveyor 18 travels in the machine direction at a first speed. The rotational speeds of blade 22 can match the conveyor speed (first speed), but in some instances, the rotational speeds of blade 22 are seen to have positive effects by having a rotational speed greater than or less than the conveyor speed.

(19) Still referring to FIG. 1, the previous description describes a horizontal conveying surface 18 at a first elevation carrying at least a first portion 14 of an article 10 to be folded. The present invention is not limited to horizontal conveying surfaces 18, but also contemplates vertical or sloped conveying surfaces 18 (not shown). When the term elevation is used in the claims, the term is not to be limited to a vertical spacing relative to the conveying surface 18, but instead should be considered a spacing in any direction away, relative to conveying surface 18, e.g., for a vertical conveyor 18, the ramp 20 would actually elevate the first portion 14 of the article 10 in a horizontal direction relatively away from the vertical conveyor 18.

(20) Referring now to FIG. 2, a side view of a folding system of the present invention is shown. In this view, the ramp 20 comprising three sections, the conveyor level 20a, the sloped midsection 20b, and the blade clearance level 20c can be seen. Referring to the first ramp in the system (upstream), right panel 14 is shown entering onto the ramp 20 at the conveyor level 20a. As the right panel 14 travels downstream, the right panel 14 travels up ramp 20 via sloped midsection 20b, raising the level of the intended target, right panel 14. As the right panel travels onto blade clearance level 20c, as shown in FIG. 3, first rotating blade 22 passes under the intended target of folding, right panel 14, and passes under blade clearance level 20c. As lobe 22a of blade 22 rotates while the right panel 14 is carried by the blade clearance level 20c, blade 22 contacts the underside of right panel 14 and folds the right panel 14 of diaper 10 over along line R, as shown in FIG. 4.

(21) Referring now to FIG. 5, with fold line R achieved, the half-folded diaper 10 is passed downstream. Left panel 12 enters onto the second ramp 20 at the conveyor level 20a. As the left panel 12 travels downstream, the right panel 14 travels up ramp 20 via sloped midsection 20b as shown in FIG. 6, raising the level of the intended target, left panel 12. As the left panel travels onto blade clearance level 20c, second rotating blade 22 passes under the intended target of folding, left panel 12, and passes under blade clearance level 20c. As lobe 22a of blade 22 rotates while the left panel 14 is carried by the blade clearance level 20c (FIG. 6), blade 22 contacts the underside of left panel 12 and folds the left panel 12 of diaper 10 over along line L, as shown in FIGS. 7 and 8. The diaper 10 is passed downstream as shown in FIG. 9, for further processing (e.g., folding or packaging) as desired.

(22) Referring now to FIG. 10, a top view of an alternate embodiment of the folding system shown in FIG. 1 is shown. In this embodiment, a tucker bar 26 is provided at or above the blade clearance level 20c, as shown in cross section in FIG. 11. The tucker bar 26 maintains the first fold R in position while the diaper is passed downstream to the second rotating blade 22 to achieve the second fold as described previously. A tucker roller 28 is optionally provided to maintain the first and second folds R and L intact during downstream passage.

(23) Referring to FIGS. 12a-c top views of alternate blade configurations are shown. In FIG. 12a, an oblong ear shaped blade 122 is shown. In FIG. 12b, a circular blade 222 is shown. In FIG. 12c, a bow-tie shaped blade 322 is shown. Blade shapes can be altered to improve folding performance. In addition, the web contacting surfaces of the blades 22, whether the web contacting surface be the top or the bottom of the blades 22, can be provided with varying coefficient-of-friction features. For instance, one portion of the blade, 22a could be provided with increased coefficient-of-friction features relative to a second portion of the blade, 22b. Alternatively, if as in FIG. 1, upstream and downstream blades 22 are used, the upstream blade 22 could provided with increased or decreased coefficient-of-friction features relative to the downstream blade 22.

(24) The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.